The kredits module always returns raw data from the contract. For uint
values these are bignumbers.
To handle those in the ember app we need to convert them to string or to
number.
To use the same code in hubot I extracted the serializer logic into lib to later move it into `truffle-kredits` when we are done with all other common logic.
This stores the GitHub username and UID in IPFS, and stores the
resulting IPFS hash in the contract. Now we can remove the GitHub
profile data from the contract entirely.