* add new route for card update
* create backend route
* update label
* basic functionality working
* ran rubocop
* added rspec tests for functionality
* make payment_method param compulsory
* fixed js linting
* improve client side error handling
* improve server side error handling
* improved update card page UI
* improve button UI for user subscriptions page
* give feedback to user about save status
* remove heading from last column
* fix padding on edit/delete buttons for update table
Co-authored-by: Blake Erickson <o.blakeerickson@gmail.com>
Faizaan Gagan