Expose location, licence and interaction data.

@pbadenski
@norm
Update the README to be more explicit.
First draft of write API.

@norm
@gtrogers
Some tests for the write API input validation.
Test POSTs write data and validate bucket names.

@norm
@gtrogers
A little tidy-up of the write API tests.
Requiring pymongo 2.4 for MongoClient import
More explicit 400 aborting in write API.

@norm
@pbadenski
Refactoring to remove module level array.

Implementing suggestions made by @robyoung
Adding script to run pep8 with some preset ignores

Also pep8-ing the api test
Pulling out methods to clarify inbound data flow.
Flipping valid data logic clarity and fewer braces
Pulling out database name to top as constant.
Adding healthcheck: _status, mimetyping responses
Testing contents of stored data.
Adding validation method for date time strings.

@gtrogers
@pbadenski
Fixing object validation to parse all fields.
Adding validation and 400'ing for _timestamp value

  NB - still saving the time stamp as a regular value in
  the database at this point.
Adding test script to fire json at api.
Storing _timestamp as a datetime object.

@pbadenski
@gtrogers