test VIM plugin with RSpec and Vimrunner

Note that to run these tests "Vim needs to be compiled with
+clientserver. This should be available with the normal, big and huge
featuresets or by using MacVim on Mac OS X. In order to start a server
without a GUI, you will also need +xterm-clipboard as described in the
Vim manual."

For more info:

https://github.com/AndrewRadev/vimrunner
http://blog.hashrocket.com/posts/vimscript-and-you?utm_source=rubyweekly&utm_medium=email