Copy data from Lat/Lon column to UTM column

This was uncovered by @cbrown -- I had assumed that the existing UTM
column was getting populated by the GTFS import process, but it's not,
so it's necessary to copy over geometry data from the WGS 84 column into
the newly-transformed UTM zone column.
Merge pull request #84 from WorldBank-Transport/feature/copy-utm-data

Copy data from Lat/Lon column to UTM column on GTFS import