prevented n+1 queries in home while loading projects labels
Merge pull request #582 from steverob/master

prevented n+1 queries in home (Project Labels)
Avoided N+1 querys in Home page coz of projects' users count; Added spec
Merge pull request #584 from jasnow/master

Upgraded gems by rebuilding Gemfile.lock file
Merge pull request #583 from steverob/master

Home page N+1 queries caused by organizations
optimize images with ImageOptim
Merge pull request #585 from acrogenesis/image-optim

optimize images with ImageOptim