This test is faking bugzilla instance via small python script (pyserve)
which accepts list of files to be served in order of appearance.

Goal is to test, if reporter-bugzilla behaves correctly when
certain criteria are met:
- no duplicate bug in bugzilla -> create new bug
- backtrace in bug has better rating -> do nothing
- backtrace in bug has worse rating than our -> upload our, better backtrace
