Allow Changing Colour of Lights

[Da-Boom]

Is your feature request related to a problem? Please describe.
I have a set of RGB lights and i would like to use mycroft to change their colour

Describe the solution you'd like
A notifty for "Change/Set <light name> to <colour>"

[Tony763]

Hi @Da-Boom, check PR #69. Feature is working, now we only wait for author of PR to fix merge issues.

[hperrin]

Brightness would also be cool.