also separate out the header joining into a function

http://pytest.org/dev/yieldfixture.html

    With pytest fixture functions, the “after yield” part will always be invoked, independently from the exception status of the test function which uses the fixture.

Use socketserver to make a temporary server which websocket tests can be run against, which takes data to return.

Probably needs extending so more checking can be done on the path etc.

Now contains a more full example of how to connect to AWS IoT platform and points to it in the documentation.

Client was stopped too early, not allowing it to always close
the connection which cause timeout in this case.

Make auth dict handling a bit more leniant

Use mutexes as context managers

Use tox to run tests

Signed-off-by: NJames Myatt <james@jamesmyatt.co.uk>

Fix for bug #3

This commit changes the logic slightly on handling of the auth dict that
gets passed in to publish or subscribe methods. Previously they expected
None to always be what is passed in which was the default. However if an
empty dict was passed in this would fail with a KeyError. Additionally
the same was true if you pased a dict in without a username key. To make
this a bit more forgiving this changes the logic so if an object is
passed in that evaluates to False (like an empty dict) the object isn't
used. It also makes checking for the presence of 'username' and
'password' use the get() method so we don't raise blank Exceptions and
are a bit more explicit in usage.

This should be fully backwards compatible with any previous usage, but
hopefully make it a bit simpler for people playing with the lib for the
first time.
Signed-off-by: NMatthew Treinish <mtreinish@kortar.org>

Start adding unit test suite in py.test

Now uses the same function as setting the path

Mentioned in #162

should already be fixed