Create a sinatra based rspec + capybara test

[goodwill]

I think we need some auto test for this to allow easier contrib validation as well as a starting point for people to understand how to use this (in case if this is not obvious enough...). My thought would be something like a very simple sinatra + rspec test. I have moved all gem files into a folder called gem so later when we use bundler to build a test project we should be able to simply use a path reference to include capybara-select2. A good reference on how to do that is here:

https://gist.github.com/juliocesar/639636

Anyone want to take on would be great as I am just too busy ATM.