* Trait.convert_value() now explicitly decodes byte strings from UTF-8:
it fixes a BytesWarning error when Python 3 is run using -bb command
line option
* Replace types.NoneType with type(None)
* fileutils.write_to_tempfile() expects content as bytes: encode the
content on Python 3
* subprocess.Popen.communicate() returns stdout and stderr as bytes:
check for pattern using byte strings
* Fix verify_signature() on Python 3: encode new signature to ASCII
* Replace "with contextlib.nested(...):" with two nested with,
contextlib.nested() was removed in Python 3
* Fix import in test_messaging
* tox -e py34 now runs much more tests
Change-Id: If2a16c3b8ca64ca86d8172b36ecbf6298044ec87
30159de5cd