The deprecations CircleCI job is failing

[exarkun]

Several tests fail like this:

Traceback (most recent call last):
testtools.testresult.real._StringException: Traceback (most recent call last):
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/twisted/trial/runner.py", line 531, in loadPackage
    module = modinfo.load()
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/twisted/python/modules.py", line 392, in load
    return self.pathEntry.pythonPath.moduleLoader(self.name)
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/twisted/python/reflect.py", line 308, in namedAny
    topLevelPackage = _importAndCheckStack(trialname)
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/twisted/python/reflect.py", line 255, in _importAndCheckStack
    reraise(excValue, excTraceback)
  File "/tmp/project/src/allmydata/test/test_auth.py", line 5, in <module>
    from twisted.conch.ssh import keys
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/twisted/conch/ssh/keys.py", line 18, in <module>
    import bcrypt
ImportError: No module named bcrypt

[GitHub <noreply@…>]

In 4bd855f/trunk:

Merge pull request #535 from tahoe-lafs/2957.circleci-deprecations

Provide compatibility with the next Twisted release

Declare a dependency on the conch extra so that we get any necessary dependencies automatically. This includes a new dependency on bcrypt.

Fixes ticket:2957