add rendering of angry goat and error messages when errors with checkout
add render orders/index to orders#update if there is an error
add ability to render angry error goat if you try to order more than stock of item
clean up extra commented-out lines of code
Merge branch 'master' into bri-cart-error-handling
Merge pull request #53 from brigid2718/bri-cart-error-handling

Bri cart error handling