Install HAML

* Add HAML to Gemfile
* Update Gemfile.lock
* Change Gemfile to receive gems from http instead of https due to certificate issues
Convert home to HAML
Change Devise register page to HAML
Change my account page to HAML
Change login page to HAML
Replace help articles in ERB with HAML
Convert application.html.erb to haml
Convert post views to haml
Merge branch 'feature/haml' into develop