Deprecations job on CircleCI fails with I2P-related errors

[exarkun]

There are 8, many of which look more or less like:

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/internet/defer.py", line 151, in maybeDeferred
    result = f(*args, **kw)
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/twisted/internet/utils.py", line 221, in runWithWarningsSuppressed
    reraise(exc_info[1], exc_info[2])
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/twisted/internet/utils.py", line 217, in runWithWarningsSuppressed
    result = f(*a, **kw)
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/allmydata/test/test_connections.py", line 234, in test_samport
    return_value=h1) as f:
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/mock/mock.py", line 1378, in __enter__
    self.target = self.getter()
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/mock/mock.py", line 1548, in <lambda>
    getter = lambda: _importer(target)
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/mock/mock.py", line 1235, in _importer
    thing = _dot_lookup(thing, comp, import_path)
  File "/tmp/tahoe-lafs.tox/upcoming-deprecations/local/lib/python2.7/site-packages/mock/mock.py", line 1224, in _dot_lookup
    __import__(import_path)
ImportError: No module named i2p

Foolscap dropped I2P support in the latest release (0.13.2) - ​https://github.com/warner/foolscap/commit/2a4501eec73e3d771894fabb1301081460cb40b5#diff-2eeaed663bd0d25b7e608891384b7298

[GitHub <noreply@…>]

In f5f27b8/trunk:

Merge pull request #675 from tahoe-lafs/3272.i2p

Pin a known working foolscap

Fixes: ticket:3272