Fixed up Gemfile and gemspec format, updated README, added spec helper and Rakefile, changed class names

:sparkling_heart: Showing the gem some :heart: 

* Moved gem dependencies from Gemfile to gemspec, removed Gemfile.lock
* Added Rakefile and rake tasks for test suite
* Added helper for test suite
* Renamed mock helper methods to remove "get_"
* Added dotenv gem, removed "testlocal" script (unrequired with `dotenv` and `.env` files :smiley_cat:)
* Removed "generic" from class names (implicit)
* Removed paths from requires in main gem file (load path in gems is implicit)
* Added gitignore for .env files
* Updated README to add more information about installation and usage (needs more work)
* Updated gemspec to include test files
* Rudely added myself to gem credits :blush: