Hash Saga Part 3 - API changes + SHA1 support + tests
remove unneeded lambdas from tests
change api.supports_hash to take a hash class rather than a str

* This change means hash class names will be byte strings and we no
  longer need to encode to ascii on hashobject.name in
  create_hash_context
change name to str
Merge pull request #123 from reaperhulk/hash-saga-sha1

Hash Saga Part 3 (API changes + SHA1)