cleanupExpiredPendingReservation - ERROR: update or delete on table "tickets_reservation" violates foreign key constraint "ticket_tickets_reservation_id_fkey" on table "ticket"

**Describe the bug**
It seems that the `cleanupExpiredPendingReservation` is failing trying to cleaning up some not finished reservations.

**To Reproduce**
Don't know how to reproduce it, sorry 😅

**Expected behavior**
What we should expect is probably let the job continue and not fail, because starting from then, all the "pending" Reservations are not going to be cancelled and ***they will remain forever*** in the system.

**Screenshots**

**Stacktrace **
```
rg.springframework.dao.DataIntegrityViolationException: PreparedStatementCallback; SQL [delete from tickets_reservation where id in (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)]; ERROR: update or delete on table "tickets_reservation" violates foreign key constraint "ticket_tickets_reservation_id_fkey" on table "ticket"
2019-12-11T23:41:14+01:00 22:41:14.081 [scheduling-1] ERROR org.springframework.scheduling.support.TaskUtils$LoggingErrorHandler - Unexpected error occurred in scheduled task.
2019-12-11T23:41:14+01:00 at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:246) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 Detail: Key is still referenced from table "ticket".; nested exception is org.postgresql.util.PSQLException: ERROR: update or delete on table "tickets_reservation" violates foreign key constraint "ticket_tickets_reservation_id_fkey" on table "ticket"
2019-12-11T23:41:14+01:00 Detail: Key is still referenced from table "ticket".
2019-12-11T23:41:14+01:00 at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:632) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.jdbc.core.JdbcTemplate.translateException(JdbcTemplate.java:1442) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:861) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:882) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at com.sun.proxy.$Proxy89.remove(Unknown Source) ~[?:?]
2019-12-11T23:41:14+01:00 at alfio.manager.TicketReservationManager.cleanupExpiredReservations(TicketReservationManager.java:1008) ~[classes!/:?]
2019-12-11T23:41:14+01:00 at org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate.update(NamedParameterJdbcTemplate.java:320) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at ch.digitalfondue.npjt.QueryType$2.apply(QueryType.java:109) ~[npjt-extra-1.1.5.jar!/:?]
2019-12-11T23:41:14+01:00 at ch.digitalfondue.npjt.QueryFactory$3.invoke(QueryFactory.java:229) ~[npjt-extra-1.1.5.jar!/:?]
2019-12-11T23:41:14+01:00 at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:749) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at alfio.manager.TicketReservationManager$$FastClassBySpringCGLIB$$e08939fb.invoke() ~[classes!/:?]
2019-12-11T23:41:14+01:00 at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at jdk.internal.reflect.GeneratedMethodAccessor62.invoke(Unknown Source) ~[?:?]
2019-12-11T23:41:14+01:00 at alfio.config.RowLevelSecurity$RoleAndOrganizationsAspect.setRoleAndVariable(RowLevelSecurity.java:139) ~[classes!/:?]
2019-12-11T23:41:14+01:00 at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
2019-12-11T23:41:14+01:00 at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
2019-12-11T23:41:14+01:00 at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:175) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98) ~[spring-tx-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:295) ~[spring-tx-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at alfio.manager.TicketReservationManager$$EnhancerBySpringCGLIB$$4598fa5.cleanupExpiredReservations() ~[classes!/:?]
2019-12-11T23:41:14+01:00 at jdk.internal.reflect.GeneratedMethodAccessor76.invoke(Unknown Source) ~[?:?]
2019-12-11T23:41:14+01:00 at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688) ~[spring-aop-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
2019-12-11T23:41:14+01:00 at alfio.job.Jobs.cleanupExpiredPendingReservation(Jobs.java:180) ~[classes!/:?]
2019-12-11T23:41:14+01:00 at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) ~[spring-context-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
2019-12-11T23:41:14+01:00 at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) [spring-context-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) [?:?]
2019-12-11T23:41:14+01:00 at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305) [?:?]
2019-12-11T23:41:14+01:00 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
2019-12-11T23:41:14+01:00 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
2019-12-11T23:41:14+01:00 at java.lang.Thread.run(Thread.java:834) [?:?]
2019-12-11T23:41:14+01:00 at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305) [?:?]
2019-12-11T23:41:14+01:00 Caused by: org.postgresql.util.PSQLException: ERROR: update or delete on table "tickets_reservation" violates foreign key constraint "ticket_tickets_reservation_id_fkey" on table "ticket"
2019-12-11T23:41:14+01:00 at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:308) ~[postgresql-42.2.5.jar!/:42.2.5]
2019-12-11T23:41:14+01:00 at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:441) ~[postgresql-42.2.5.jar!/:42.2.5]
2019-12-11T23:41:14+01:00 Detail: Key is still referenced from table "ticket".
2019-12-11T23:41:14+01:00 at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2440) ~[postgresql-42.2.5.jar!/:42.2.5]
2019-12-11T23:41:14+01:00 at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2183) ~[postgresql-42.2.5.jar!/:42.2.5]
2019-12-11T23:41:14+01:00 at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:365) ~[postgresql-42.2.5.jar!/:42.2.5]
2019-12-11T23:41:14+01:00 at org.postgresql.jdbc.PgPreparedStatement.executeUpdate(PgPreparedStatement.java:120) ~[postgresql-42.2.5.jar!/:42.2.5]
2019-12-11T23:41:14+01:00 at com.zaxxer.hikari.pool.ProxyPreparedStatement.executeUpdate(ProxyPreparedStatement.java:61) ~[HikariCP-3.3.1.jar!/:?]
2019-12-11T23:41:14+01:00 at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.executeUpdate(HikariProxyPreparedStatement.java) ~[HikariCP-3.3.1.jar!/:?]
2019-12-11T23:41:14+01:00 at org.postgresql.jdbc.PgPreparedStatement.executeWithFlags(PgPreparedStatement.java:143) ~[postgresql-42.2.5.jar!/:42.2.5]
2019-12-11T23:41:14+01:00 at org.springframework.jdbc.core.JdbcTemplate.lambda$update$0(JdbcTemplate.java:866) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE]
2019-12-11T23:41:14+01:00 ... 39 more
```

**Version:**
v.2.0-M2-SNAPSHOT

**Desktop (please complete the following information):**
N/A

**Smartphone (please complete the following information):**
N/A

**Additional context**
Add any other context about the problem here.