Allow expected errors to also handle linting

[dreispt]

Expected error check is moved from server tests to the test controller travis_run_tests.
This allows to expect for types of errors other than server errors, such as lint errors.

Extracted from the PR #223

[yvaucher]

Thanks for the extraction 👍

[moylop260]

IMHO expected errors of lint should process it each lint script for compatibility with git_hook and use a particular variable by each script to major control.

To know if this work we will need to add some lint errors to MQT.

This change is indeed here: #226
Maybe I will need to add @dreispt author in the commit of this functionallity and discuss this change in other one.

[moylop260]

Other matter is that using the pylint from python you can get a counter of errors (Don't just exit(1 or 0))
Of this way you can to check that you have the exactly errors expected counters.
NOTE: To use python package we need to migrate pylint to python script... to check that works we need add lint tests cases.

[moylop260]

This feature now was merged in next PR:
#230

@dreispt
Can you extract the fix part of travis/travis_install_nightly and create a new PR?

IMHO this PR should be closed.