Dlhub-sdk

Major overhaul of the DLHubClient:

- Send authorization headers with each request
- Add utilities for managing credentials
- Add publication from local system with HTTPS uploads

Switching to Travis CI for running the PyPi deployments.

Added required dependencies for the Client to setup.py

- Updated the URL of DLHub API server
- Added initial draft of documentation

Fixed bug in `setup.py`. The previous version failed to get all of the modules of `dlhub_sdk`

v.0.1.0
First version dlhub_sdk suitable for public use