VCR.py simplifies and speeds up testing HTTP by recording all HTTP interactions
and saving them to "cassette" files, which are yaml files containing the
contents of your requests and responses. Then when you run your tests again,
they all just hit the text files instead of the internet. This speeds up your
tests and lets you work offline.
If the server you are testing against ever changes its API, all you need to do
is delete your existing cassette files, and run your tests again. All of the
mocked responses will be updated with the new API.