* Adds MoldIndicator sensor platform
This sensor may be used to get an indication for possible mold growth in rooms.
It calculates the humidity at a pre-calibrated indoor point (wall, window).
* Automatic conversion to Fahrenheit for mold_indicator
* Minor change to critical temp label
* Fixed docstrings and styles
* Minor changes to MoldIndicator implementation
* Added first (non-working) implementation for mold_indicator test
* Small style changes
* Minor improvements to mold_indicator
* Completed unit test for mold indicator
* Fix to moldindicator initialization
* Adds missing period. Now that really matters..
* Adds test for sensor_changed function