Alternative to including landsat\scene_list.txt is desireable

[Jwely]

presently, the scene_list.txt file makes up about 95% of the dnppy space requirement. This information isn't easily found online since it is only available for download in compressed format from AWS here:
http://landsat-pds.s3.amazonaws.com/scene_list.gz

The current solution is to simply include it in the dnppy package, but this isn't preferred.

[Jwely]

this issue was solved by fetching a fresh copy of the scene_list.txt every time the fetch_landsat8 function is called.