Bump version to 0.5
Bump version to 0.5

This includes:

* Fix add_child_sensor to not add child_ids already in children.
* Handle message-type req.
* Add kwargs to set_child_value functions.
* Fix PEP issues in all files.
* Remove sleep in connect function.
* Add threading.lock for send function.
* Fix decode partial data.

theolind/pymysensors,afeno/pymysensors,Br3nda/pymysensors