began hardening the /certificate/sign endpoint
improved signer worker crash handling
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Merge pull request #283 from dannycoates/signer

Improved /certificate/sign stability
Add token derivation test vectors to unittest suite.
how'd that get there?
Merge pull request #285 from mozilla/token-test-vectors

Add token derivation test vectors to unittest suite.
extracted test_server from integration_tests etc
Merge pull request #284 from dannycoates/i284

Factor test-server spawn/teardown code into a single helper function