Closes #774 - centers logo animation

Fixes off center animation by rotating it full circle
Consistant placeholder between chrome and firefox
Minor CSS fixes
Update autoprefixer-rails to version 4.0.2.1
Update email_validator to version 1.5.0
Update newrelic_rpm to version 3.9.8.273
Update nokogiri to version 1.6.5
Update puma to version 2.10.2
Update rails-erd to version 1.2.0
Update rake to version 10.4.2
Update redis to version 3.2.0
Update netrc to version 0.10.1
Update uglifier to version 2.6.0
Merge pull request #792 from rubygems/ac-774-center-logo-animation

#774 - centers logo animation
Updated stats styles