Cleans up code base and removes non-working code   - Cleans up code for consistency and pythonic standards   - Adds helper functions   - Adds preliminary cache Directory functions for downloadEntity   - Makes some of the user facing functions similar to the R client.   - comments out all unitests until they can be modified to work with new layout.
Cleans up code base and removes non-working code
  - Cleans up code for consistency and pythonic standards
  - Adds helper functions
  - Adds preliminary cache Directory functions for downloadEntity
  - Makes some of the user facing functions similar to the R client.
  - comments out all unitests until they can be modified to work with new layout.

kkdang/synapsePythonClient,thomasyu888/synapsePythonClient,larssono/synapsePythonClient,zimingd/synapsePythonClient