Update nginx
Update mongo, node, php, python, rails, ruby

For details of the ruby and rails changes, see https://github.com/docker-library/ruby/pull/21 and https://github.com/docker-library/rails/pull/12.
Merge pull request #272 from infosiftr/update-docker-library

Update mongo, node, php, python, rails, ruby
Merge pull request #269 from Morhaus/master

Update nginx