Reset Timecop after every test
Constrain the tests to the specific time range
Time travel to the start of the new agricultural year

This test could break depending on which part of 
the year you run it. I think this only worked
because we never reset Timecop after running a test.
Set the time for state pension integration test
Merge pull request #273 from alphagov/fix-time-based-tests

Fix time based tests