Update gems in bundle.

Here's what changed:
Installing better_errors 2.0.0 (was 1.1.0)
Installing nokogiri 1.6.3.1 (was 1.6.2.1)
Installing capybara 2.4.1 (was 2.3.0)
Installing coffee-script-source 1.8.0 (was 1.7.0)
Installing execjs 2.2.1 (was 2.2.0)
Installing coffee-script 2.3.0 (was 2.2.0)
Installing devise 3.3.0 (was 3.2.4)
Installing faker 1.4.3 (was 1.4.2)
Installing font-awesome-sass 4.2.0 (was 4.1.0)
Installing hashie 3.3.1 (was 2.1.2)
Installing jbuilder 2.1.3 (was 2.1.1)
Installing minitest-rails 2.1.0 (was 2.0.3)
Installing minitest-rails-capybara 2.1.1 (was 2.0.1)
Installing oauth2 1.0.0 (was 0.9.4)
Installing omniauth 1.2.2 (was 1.2.1)
Installing omniauth-oauth2 1.2.0 (was 1.1.2)
Installing slop 3.6.0 (was 3.5.0)
Installing pundit 0.3.0 (was 0.2.3)
Installing sdoc 0.4.1 (was 0.4.0)
Installing turbolinks 2.3.0 (was 2.2.2)
Installing uglifier 2.5.3 (was 2.5.1)