timeout for Math-2 , Math-5, Math-8, Math-28

Flacoco reaches the timeout for bug Math-2

See log here:
https://github.com/martinezmatias/astor/runs/3676644171?check_suite_focus=true#step:8:1199

````
java.lang.RuntimeException: Forked process did not finish correctly. Timeout set was 5400000 ms, process took 5400000 ms before ending.
Finishing execution for Math2: # patches: 0
at eu.stamp_project.testrunner.EntryPoint.runGivenCommandLine(EntryPoint.java:764)
at eu.stamp_project.testrunner.EntryPoint.runOnlineCoveredTestResultPerTestMethods(EntryPoint.java:656)
at fr.spoonlabs.flacoco.core.coverage.framework.JUnit4Strategy.execute(JUnit4Strategy.java:27)
at fr.spoonlabs.flacoco.core.coverage.CoverageRunner.getCoverageMatrix(CoverageRunner.java:49)
at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.computeCoverageMatrix(SpectrumRunner.java:56)
at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.run(SpectrumRunner.java:32)
at fr.spoonlabs.flacoco.api.Flacoco.run(Flacoco.java:31)
at fr.inria.astor.core.faultlocalization.flacoco.FlacocoFaultLocalization.searchSuspicious(FlacocoFaultLocalization.java:44)
at fr.inria.astor.core.solutionsearch.AstorCoreEngine.calculateSuspicious(AstorCoreEngine.java:906)

....

````

Similar for Math-5

https://github.com/martinezmatias/astor/runs/3676644222?check_suite_focus=true#step:8:1589

for Math-8:

https://github.com/martinezmatias/astor/runs/3676644282?check_suite_focus=true#step:8:375