Test on ruby 2.1
Bump image_optim from 0.9.1 to 0.10.2
Merge pull request #14 from plasticine/update-deps

Update image_optim to 0.10.2
Merge branch 'master' of git://github.com/jagthedrummer/middleman-imageoptim

Conflicts:
	middleman-imageoptim.gemspec