Merge pull request #44 from plusjeff/rails-5.0.0

Upgrade to Rails 5.0.0

Author: tianon

Dockerfile

@@ -6,6 +6,6 @@ RUN apt-get update && apt-get install -y nodejs --no-install-recommends && rm -r
 # see http://guides.rubyonrails.org/command_line.html#rails-dbconsole
 RUN apt-get update && apt-get install -y mysql-client postgresql-client sqlite3 --no-install-recommends && rm -rf /var/lib/apt/lists/*
 
-ENV RAILS_VERSION 4.2.6
+ENV RAILS_VERSION 5.0.0
 
 RUN gem install rails --version "$RAILS_VERSION"