Add in Rubocop, SimpleCov, and RSpec support and fix stylistic errors. Closes #18

[Tristor]

This is a squashed set of four commits. The original commit messages are below in commit order:

• Add in a Rubocop configuration tuned from my usual and updated to work with latest Rubocop. 115 offenses found.
• Fixed stylistic and layout changes from Rubocop, as well as a few syntax issues which were in likely rarely triggered code paths. 115 -> 5 offenses in Rubocop.
• Add in dependencies for Rubocop, RSpec, and SimpleCov, add in a spec_helper, and add in correct tasks in Rakefile
• Add in configuration for RSpec and CodeClimate. You can add CodeClimate to public repos for free.

This closes Lyle-Tafoya/Steam-Categorizer#18

[Tristor]

If it helps any, I'm doing a test-run of the tool right now. So far it appears to be working nicely. Thanks for writing this, I was looking for something like Depressurizer for OS X. I've got several thousand games though so with only 16 threads it's going to take awhile. I'll bump this if I get a clean run, but none of my changes here-in should have broke anything.

[Tristor]

Okay, I did break something, but it's fixed now. Everything looks gold. Let me know if you need me to change anything here :)

[Lyle-Tafoya]

I just tested this and merged it in. Thanks for setting this up!