Use double() for mocks instead of simple values
Use double() for mocks instead of simple values

spec/spec_helper.rb was generated with
  mocks.verify_partial_doubles = true
causing Rspec to check mocked methods against the type being mocked

This led to warnings that...
  'true' does not support :lists
  '[]'   does not support :subscribe

ddmck/Empirical-Core,ddmck/Empirical-Core,ddmck/Empirical-Core,ddmck/Empirical-Core