Merge pull request #11 from kalfa/master

pass SerialClass to rfxcom.transport.base.BaseTransport
Updated the README.
call_later should call write() not its result
unit test for AsyncioTransport rewritten for constructor and setup

The idea is removing the dependancies, which in this case are the loop
and the device objects, and testing only their role with
AsyncioTransport
Merge pull request #12 from kalfa/master

call_later should call write() not its result
Greatly improved README.
Fixed a typo in the README.
Updated the docstring for the RFXtrx setup
Fixing rst link to Read the docs
Improve testing of the transport base and asyncio
Updated badges alt's
Add StubSerial and related StubbedDefaultSeletor
Use the StubSerial class, if specified at commandline