Testing deuceclient

DEPENDS: PR #6 

Adds nearly all testing required to Deuce Client
Adds some bug fixes discovered during testing

Also, as a review, I noticed the following:
- Notable functionality missing:
  - Listing Vaults
  - Finalizing a File
  - Non-Auth Auth
- Notable Improvements:
  - Structure; callers need to know too much about the Deuce API