Refactor all strategy tests

[drvinceknight]

With the merge of #875 we have a new method for testing strategies called versus_test (http://axelrod.readthedocs.io/en/latest/tutorials/contributing/strategy/writing_test_for_the_new_strategy.html). The goal is for this to eventually replace the currently used responses_test.

This will take a slow refactor of all strategy tests. Ideally any PRs towards this issue should only do a small number of modules at a time to ensure that nothing is missed during the review process.

EDIT: Once all of these are complete, we can refactor the TestPlayer class to remove unused methods.