Updating server resources upload

[davidorme]

This PR is to address #102:

• Moves the server functionality from zenodo into its own server module
• Updates the API documentation to add that module and fix references.
• Updates the server.upload_gazetteer funciton to server.upload_resources including the project database.
• Verifies that the payload is received and handled correctly over in safedata_server.

It also documents the previously hidden show_resources subcommand and updates the similar safedata_zenodo show_config to use the same name.

Fixes #102

[davidorme]

The problem with solving #57 is that the function in zenodo and server need to interact with an external resource. I had the same thing with safedata which now mocks those interactions. I think that is the way forward here but it's a little bit more involved. Both zenodo and server would use the same mocked approach so might as well bundle them.