Fixes move to HTTPS

Thanks for @paumoreno this new release works now that the NASA server only accepts HTTPS.

Bugfix release, works with EarthData logins

I screwed up the last version while cleaning up the codebase, it now seems to work reasonably well. You will need to call the script with your username and password as this (for example)

./get_modis.py -u USERNAME -P PASSWORD-v -s MOTA -p MCD45A1.051 -t h13v10 -y 2010

Now working with EarthData Login credentials

The aim of this release is to make the code work with the new requirements from NASA to use authentication. This now works, but at the cost that the requests module is required. As usual, not tested for Python3 compliance ;-)