The bot has no tests

[betatim]

Currently it takes a long time/a lot of CPU to verify that the bot still works. Create tests that use mock to replace the slow running bits so that we can verify that the bot still works.

Steps:

• setup py.test
• create the simplest test possible that tests something
• test with a mock that picking a random location works
• test with a mock for downloading images
• create a test that mocks posting to twitter