Clear fakeweb registry before each test

@maxfliri
Conform to backdrop API for licences

@abersager
@maxfliri
Conform indivdual licence request to backdrop API

@abersager
@maxfliri
Temporarily disable retrieval of licence name

The feature is not available yet from the backend

@abersager
@maxfliri
Fix filter_by syntax

@abersager
@maxfliri
use authority name and licence name only when available in the response.

@maxfliri
@abersager
allow missing data points in applications graph time series
Merge pull request #17 from alphagov/use-backdrop-api

Use backdrop api