Added RTU mode

Added RTU mode, but not tested it. Feedback would be appreciated!

Added initialization checks

Integration fails to load if not able to ocmmunicate with device. This makes sure that we read data before loading entities etc. This also gives better feedback when updates fail

Fix units Trox TVE

Dynamically loading flow units on first read

Bugfix Swegon R15

v1.0.1

Update CASA_R15.py

First release

Have fun :)