Use callback in Mashify middleware.
Update gemspec for Faraday 0.9.0
Fix Proxy test for all current Faraday versions
Fix Mashify test to work with Faraday callback
Only patch Multipart-Post if neccessary, don't hardcode content-type
Remove errant "require 'pry'"
Merge pull request #124 from crisply/dan/faraday-0.9

Update code for Faraday 0.9
Bump version.