There's another warning now, one raised by msgpack because unpackb(...,
encoding=encoding) has been deprecated, since version 0.5.2

At first I wanted to update the calls to unpackb, and use the new
raw=False, but then we would require 0.5.2 or later, and that version
does not support Python 3.4 anymore. So, if we want to support Python
3.4 we have to live with this warning.

This failure probably is because Travis runs the tests for every
environment in parallel. And depending on the timing, a message is
published in one environment, and unexpectedly read from another.

Fixed changing the name of the channel.

Update README with supported platforms

Fix tests

Fixes #104

Fix README so it doesn't mislead ttl to be in s

Fixes #133