Fixed category plurality
Implemented a new menu for desktop, and modified the menu for small screens.
Merge branch 'feature/menu' into develop
Add ability to add an instructor from the course admin page

Fixes #14
Fixed index view now getting instructors properly
Decreased color intensity of menu borders.
Adjusted menu letter spacing
Cleaned up css file of old menu code.
Added function comments.
Started work on editing a profile.
Form now submits with email check.
Added a password change form.
Fixed main page still showing the sign up button when a user is logged in.