Requirements.txt

Memberships 
* User should see link for Basic plan on home page
* User should see link for Pro plan on home page
* Basic plan link should point to regular Devise sign up form
* Pro plan link should point to a custom sign up form

Stripe Integration
* Users should have a stripe customer token in the users table.
* Javascript should prevent Pro form from submitting after user fills it out, and should
send card info to Stripe. Stripe will return with a card token.
*Javascript should send user fields and card token to our rails app. Rails app should
validate the user fields. Rails app will note whether plan 1 or plan 2.
*Once validated, Rails should send user info (email, plan id) and card token to Stripe
server and Stripe will create a subscription and send back customer token. Rails should
save customer token and user information to our database.