Add vcr_config to conftest to filter headers and auto-decompress resp…

[theferrit32]

…onses. Refresh and clean up all cassettes. Remove all_played checks.

Close #588

[jsstevenson]

Motivation behind removing all_played?

[theferrit32]

@jsstevenson I think these tests should be primarily concerned with the outputs being correct. I don't think the test should fail if an http request which was previously made was not made during a particular run, if the output is still correct. When we're testing the VCF annotator we shouldn't really be concerned with checking the number of http requests made. The cassettes can be cleaned out by just deleting them all and then running again to re-generate them.

I was hitting problems with tests sometimes failing even though the outputs were correct. I think partially related to some lru_cache having or not having a value, and making a test either store another cassette, or skip a cassette, when I wanted to run a single test function or run the tests out of order.