Automatically check failing tests in get_trigger do not result from configuration issues.

[rrrrrrockpang]

In this step (Reproducing Bugs, get_trigger.pl) , we need to a way to automatically check whether each bug candidates exist in the trigger_tests folder. The script should flag bugs for manual inspection.

Below is the pseudocode:

flagged_bugs = []
For rev_entry in rev pairs:
    check if the bug id exist in trigger test
    if no:
        determine the revision hash of the fixed version from active-bugs.csv
        look up failing test of the revision hash
        run mvn test
        
        if the errors are consistent / the number is different
              continue
        else
               flagged_bugs.append(rev_entry)