Split up tests
Recursively load unit test files
Add tests for pylint checker
Replace submodules with local package management
Add another test for pylint
Add explanatory comments to test resources
Test a real syntax error in pylint
Add tests for flake8
Add tests for bash
Remove unused requires
Add tests for Perl
Test flake8rc
Move require to proper place
Add tests for Zsh checker
Add tests for xmlstarlet checker
Merge branch 'master' into unit-tests
Fix checker symbols in unit tests

Following ae58758
Enforce the proper shell type in unit tests
Make same-files-p test independent of parent dir
Provide VM to test flycheck

This VM has all necessary checker tools and supported Emacs versions
installed, and can be used for quick and easy testing.