Pull request from Sam, Alex, Thomas, and Christian

Here's what we did:

-- Sign up is now connected to home page
-- Upon clicking sign-up button, modal opens
-- Any errors in user creation will show up on homepage and will not create a user (this is not the most user-friendly way to display error messages, but any errors were breaking the flow of the views, so this was a quick solution)
-- Added js file in "assets" for modal functionality
-- Added controller logic to discern between Q/A/C's
-- Played with testing and Capybara