Added paperclip to gemfile, production.rb config
Added file attribute to Spark.
Added file attribute to SparksController whitelist.
Added ImageMagick stuff.
Added test image to spec folder.
Set up existing Spark specs with file attribute.
Added file specs to Spark model.
Testing for file attribute on Sparks json view.
Added file attribute to JSON views for Sparks.
Replaced before(:each) calls with before calls.
Added mini imagemagick gem
Removed unneeded mini_magick gem
Updated seed data for new file stuff.
Merge pull request #71 from maxluzuriaga/paperclip

Paperclip file uploading (for the API)