adds balanced gem. Requires balanced in air_cycle.rb and adds test key to env
adds balanced.js to asset pipeline
adds customer_id to users. adds respective methods in both in_mem and orm. adds Transactions module
adds get_customer_id_by_user_id db method
finishes AddPaymentMethod use case. needs to send json response back to client side. last test needs to be strengthened.
pre merge
Merge branch 'development' of https://github.com/felguerez/aircycle into balanced-api

Conflicts:
	db/schema.rb
	web/app/assets/javascripts/application.js
Merge pull request #104 from felguerez/balanced-api

Balanced api