Use Module#refine in everypolitician_extensions.rb

[chrismytton]

Problem

We're currently monkey patching the Everypolitician module in everypolitician_extensions.rb. These changes are global, so could potentially stand on the toes of other code without realising.

Proposed Solution

Use Module#refine to make changes to the Everypolitician::* classes so that our changes are local to the application.

Acceptance Criteria

Changes that are made to Everypolitician should be scoped to the application.