add gzip middleware
automatically load all middleware by requiring 'ridley/middleware'

no extra steps now needed for creating new middleware and adding it to Ridley. Just
create a new middleware file and put it in lib/ridley/middleware
add specs for gzip middleware
Connection#stream will respect gzip and deflated content types
Merge pull request #115 from RiotGames/gzip-middleware

Doesn't notice when cookbook data is gzipped