1117 factory boy

@tobes @vitorbaptista @domoritz @joetsoi This is <https://github.com/okfn/ckan/pull/1117> but using [factory_boy](http://factoryboy.readthedocs.org/en/latest/) instead of our "static test data" module for creating the test fixtures.

I'm probably going to pull this into <https://github.com/okfn/ckan/pull/1117> but wanted to put it on its own branch first so people can comment.