Continuous migration test data have invalid mongo json

## Describe the bug
Checked a test data file schema1_data.json and saw it is invalid. More precisely, it has an extra comma at the end in the fields array.

## Clean data
```json
{ "_id" : ObjectId("5a02c0799b2c26c8fc064e01"), "name" : "TestSchema1", "version" : 1, "description" : null, "dateCreated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userCreated" : "migration", "lastUpdated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userUpdated" : "migration", "disabled" : false, "dateDisabled" : null, "userDisabled" : null, "fields" : [ { "name" : "testId1", "type" : "long", "path" : "testId1", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] }, { "name" : "testName", "type" : "string", "path" : "testName", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] } ], "parent" : null }
{ "_id" : ObjectId("5a02c0799b2c26c8fc064e03"), "name" : "TestSchema2", "version" : 1, "description" : null, "dateCreated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userCreated" : "migration", "lastUpdated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userUpdated" : "migration", "disabled" : false, "dateDisabled" : null, "userDisabled" : null, "fields" : [ { "name" : "testId2", "type" : "long", "path" : "testId2", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] }, { "name" : "testName", "type" : "string", "path" : "testName", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] } ], "parent" : null }
{ "_id" : ObjectId("5a02c0799b2c26c8fc064e13"), "name" : "TestSchema2", "version" : 2, "description" : null, "dateCreated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userCreated" : "migration", "lastUpdated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userUpdated" : "migration", "disabled" : false, "dateDisabled" : null, "userDisabled" : null, "fields" : [ { "name" : "testId3", "type" : "long", "path" : "testId3", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] }, { "name" : "testName", "type" : "string", "path" : "testName", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] } ], "parent" : null }
{ "_id" : ObjectId("5a02c0799b2c26c8fc064e23"), "name" : "TestSchema2", "version" : 3, "description" : null, "dateCreated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userCreated" : "migration", "lastUpdated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userUpdated" : "migration", "disabled" : false, "dateDisabled" : null, "userDisabled" : null, "fields" : [ { "name" : "testId4", "type" : "long", "path" : "testId4", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] }, { "name" : "testName", "type" : "string", "path" : "testName", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] } ], "parent" : null }
{ "_id" : ObjectId("5a030d819b2c26c8fc069105"), "name" : "TestSchema3", "version" : 1, "description" : null, "dateCreated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userCreated" : "migration", "lastUpdated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userUpdated" : "migration", "disabled" : false, "dateDisabled" : null, "userDisabled" : null, "fields" : [ { "name" : "testId5", "type" : "long", "path" : "testId5", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] }, { "name" : "testName", "type" : "string", "path" : "testName", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] } ], "parent" : null }
{ "_id" : ObjectId("5a030d819b2c26c8fc069115"), "name" : "TestSchema4", "version" : 1, "description" : null, "dateCreated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userCreated" : "migration", "lastUpdated" : { "dateTime" : { "date" : { "year" : 2019, "month" : 6, "day" : 7 }, "time" : { "hour" : 13, "minute" : 4, "second" : 56, "nano" : 104000000 } }, "offset" : 7200, "zone" : "Europe/Prague" }, "userUpdated" : "migration", "disabled" : false, "dateDisabled" : null, "userDisabled" : null, "fields" : [ { "name" : "testId6", "type" : "long", "path" : "testId6", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] }, { "name" : "testName", "type" : "string", "path" : "testName", "elementType" : null, "containsNull" : null, "nullable" : true, "metadata" : {}, "children" : [] } ], "parent" : null }
```