Implementation of token auth for storage server and sample blob data type

Base on latest ID-Attached-Data spec: https://wiki.mozilla.org/Identity/CryptoIdeas/03-ID-Attached-Data
auth should return Hapi error on unknown token, fix comments
add api for deleting accounts
install couchbase on the server aws deployment
Merge pull request #16 from mozilla/token-auth

Implementation of token auth for storage server and sample blob data type