Fix tests with ZODB >= 5.6.0.

See https://github.com/zopefoundation/ZODB/pull/207

Update package link from pypi.python.org to pypi.org

Documentation draft

Replace deprecated occurences of Thread.isAlive() by Thread.is_alive()

The variable is named `address` and is called `addr` in the following lines. This PR use `address` consistently.

Use of --configure option instead of --configuration

fix Py3 SSL tests by providing proper CA test certificates

Fix typo

Use a temporary directory in tests

Otherwise when you run `tox` this test will create a `data.fs` using
Python 2 and then the same test will fail on Python 3 because there
already is a `data.fs` in the current working directory, but it has an
incompatible format.

Stop calling the deprecated checkSecure method.

Fixes #134.

* Additionally test PyPy3 on TravisCI.
* Handle additional `context` argument of Python 3.7 gracefully.

Fixes #116.

Fix tests under ZODB 5.5

Based on discussion beginning https://github.com/zopefoundation/ZODB/pull/222#issuecomment-441398381

Use pickle protocol 3 on the wire.