Update geotag_from_gpx.py

typo's? should be `gpxpy`
Merge pull request #15 from mprins/patch-1

fix typo in  geotag_from_gpx.py
actually use the time_offset parameter

the time_offset parameter is being ignored; this should fix that
Merge pull request #16 from mprins/fix_time_offset

Actually use the time_offset parameter
upload: remove imgDirection requirement and better handling of time