Convert double quote the single quote

Conflicts:
  Gemfile
Add gem for use in rspec
Create 'spec_helper.rb'
Execute 'rails g rspec:controller girls'
Not use camel case
Merge branch 'master' of github.com:sachin21/jd-rank into write_specs

Conflicts:
  Gemfile.lock
  spec/controllers/girls_controller_spec.rb
  spec/spec_helper.rb