* Test PyPy 3.5-5.7.1-beta

Add a missing `clear` method to the tblib Frame object.

[skip appveyor]

* Add PyPy3.5 tests

* Standard PyPy fixes for imported tests.

* more gevent/pypy3.5 blackouts and missing cert files

* another blackballed test due to performance issues.

* missing revocation.crl for test_ssl.py

* Fix test_urllib2_localnet. We had to resort to a patch.

* Adjust timeouts for PyPy3.

* Add test_wsgiref for 3.5 and 3.6 and comment about it being broken

It's broken for all of them, not just PyPy, so move its patch to
reflect that.