Updated link to NLCD 2016, modified unzipping and content removal

[jmichellehu]

No description provided.

[dshean]

Thanks for updating with 2016 data. I think we probably want to preserve some of the functionality to download and prepare the 2011 data, rather than delete. Simple option is to comment out the 2011-specific code. Better would be to download both, or implement logic allowing the user to select the version to download (can just hardcode variable for now).

Did you verify that the final output tif files are interchangeable in terms of format, values, dimensions, etc.? Don't want to break demcoreg masking functionality that expects the 2011 tif.

[jmichellehu]

Output tifs seem to be interchangeable (can't access the original 2011 url to fully test, but the updated link to 2011 dataset matches 2013 and 2016). Added some handling to select years too.