Trying to issue a credit on a non-creditable card throws uninformative error

[stith]

If you try to:

balanced.get("/cards/ABCDEFG").credit({
  amount: "1000",
  description: "Test!"
})

But the card with ID ABCDEFG has can_credit == false, I'm seeing a very vague error:

TypeError: Cannot read property 'href' of undefined
    at jsonapi._getLink (/vagrant/node_modules/balanced-official/node_modules/jsonapi-client/lib.js:179:44)
    at /vagrant/node_modules/balanced-official/node_modules/jsonapi-client/lib.js:497:34
    at _fulfilled (/vagrant/node_modules/balanced-official/node_modules/jsonapi-client/node_modules/q/q.js:787:54)
    at self.promiseDispatch.done (/vagrant/node_modules/balanced-official/node_modules/jsonapi-client/node_modules/q/q.js:816:30)
    at Promise.promise.promiseDispatch (/vagrant/node_modules/balanced-official/node_modules/jsonapi-client/node_modules/q/q.js:749:13)
    at /vagrant/node_modules/balanced-official/node_modules/jsonapi-client/node_modules/q/q.js:810:14
    at flush (/vagrant/node_modules/balanced-official/node_modules/jsonapi-client/node_modules/q/q.js:108:17)
    at process._tickDomainCallback (node.js:372:11)

It'd be much more helpful if we instead got an error indicating that the card cannot be credited.