Add production support

[realumhelp]

Fixes #1 -

Filled in many blanks left in the TED5000 interface and commonized as much as I could to get it in a place where it can parse Production and Consumption MTU's. Used http://demo.theenergydetective.com to test against since I don't have a TED5000 system. Got the TED5000 fixtures from the demo.

The TED6000 side didn't change a whole huge amount but I did do a bit a math to make the values coming from TED5000 and TED6000 the same.

Interface Changes:

• The MtuConsumption namedtuple was renamed to MtuNet and a field was added "type" which represents either Production or Consumption based on the MTU Type. Also the field "current_usage" was renamed to "now" to be more generic if the MTU is producing

• The mtu_consumption function was modified to mtu_value

  Unfortunately, it will break the HA code that currently exists. I think it should be easy enough to fix though. There is much less differentiation between TED5000 and TED6000. Both interfaces should be producing very similar data.

[realumhelp]

Looks great! Thank you so much for digging into the API and fixing my typos. It looks like you spent a lot of time on this, and I'm glad you even added lots of tests!

I added a few a comments in the review. Hopefully I am not being too picky.

I hopefully resolved all of your comments.

[rianadon]

Awesome! Thank you so much!