Add AqaraSmartBulbE27 support

[starkillerOG]

Also add untested bind commands to docstring from #295

Add AqaraSmartBulbE27 support from https://github.com/igzero/xiaomigateway

Note that the self._props.color_temp = self.send("get_ct").pop() is untested but that seemed to be a very good guess as:
set_ct
set_bright
get_bright
are implemented in https://github.com/igzero/xiaomigateway

[starkillerOG]

@igzero Could you test this code?
If so it will be straigt forward to add the bulb to HomeAssistant in the official xiaomi_miio component.

[coveralls]

Coverage decreased (-0.07%) to 74.218% when pulling 8320f6f on starkillerOG:patch-10 into 8a88057 on rytilahti:master.

[starkillerOG]

@rytilahti can you merge this?
All tests pass (except coverage)

[starkillerOG]

@mouth4war did you test this code?

[rytilahti]

Sure thing! I think we should start adding some tests for the gateway to avoid breaking it inadverently in the future. That's probably best done in sync with refactoring the file into its own package as discussed earlier.