Add the home page carousel tothe how it works page
Move the home carousel into a partial]
Add home carousel, title, and fix text on how it works page
Merge pull request #985 from teamleada/mark-style-how-it-works

Style the how it works page
Style fix for next_link and back_link
Find through lesson, not url
Merge pull request #986 from teamleada/mark-project-step-bug

Fix the project next_step bug
Create project sets
Add project set seed file
Annotate project sets and evaluation contents
Add project set id to projects
Add project_set relationship to projects
Add methods to check if a project belongs to a set or not
Add 'displayable' method