Testing

[knl]

This issue will track the tasks to add testing of this package.

[ ] Add regression tests
[ ] Add travis-ci integration

This might be impossible, due to:
https://www.gnu.org/software/emacs/manual/html_node/elisp/Color-Names.html

Which effectively says the colors depend on the display the emacs'es frame is running on. Hence, if a tests are run in a shell, which is in a terminal that has its custom theme, colors may be off...