Don't use with nokogiri >= 1.6.4

https://github.com/sparklemotion/nokogiri/issues/1196
Update activesupport to 4.1
Refactor to use Example class instead of hash of hashes
Simplify setting of the default file suffix in SuiteParsers
Completely refactor

...for the last time, really.
Add rspec tests
Setup SimpleCov, CodeClimate and Travis
Improve readibility of diff with extra padding
Allow to use shorten module name
Update readme