* Add option to open loclist/quicklist when there are errors
I copied PR #137, and tries to complete it by correcting some issues and
adding vader tests.
About tests, first time with vader, can you give some feedback if there
are what you expected in PR #137.
* Remove old code + fix indent issue
* add g:ale_keep_list_window_open option
* Correct bug with keep open option
* Add comment into vader file
* Fix errors for Travis CI build