filter on asset_type == combiner

[williamhobbs]

I added a filter in the second to last code block to only grab combiners. There are no asset_type = inverter in the sample geojson file, but I talked about the option to add them, so I think it makes sense to filter on asset_type, just in case someone builds off of the demo.

changed this:

data_centroids = pd.DataFrame(data_utm.centroid.get_coordinates().values, index=data_utm.asset_name, columns=['E', 'N'])
data_centroids.head()

to this:

data_boundaries = data_utm.loc[data_utm['asset_type']=='combiner']
data_centroids = pd.DataFrame(
    data_boundaries.centroid.get_coordinates().values,
    index=data_utm.asset_name, columns=['E', 'N']
    )
data_centroids.head()

[jranalli]

Good addition, I will merge this later today.