Installed RSpec

I installed a basic RSpec setup for testing the gem. I have yet to
write any tests.
Removed the Ability to Name Stevenson Files Oddly

I limited the naming convention for _stevenson.yml files to only
include `_stevenson.yml`. I don’t think dot files are a good idea here.
Fixed Some Mistakes in the License and Gemspec
Added a Test

I added one test to check that the app exits when an invalid template
is used
Merge branch 'adding-rspec' into development
Merge branch 'development'