bearing_to_lonlat: Get spatial coordinate given an origin, a great circle...
In Michael-Stevens-27/silverblaze: Geographic Profiling in R

Calculate destination lat/lon given an origin, a great circle distance of travel, and a bearing.

1	bearing_to_lonlat(origin_lon, origin_lat, bearing, gc_dist)

`origin_lon`	The origin longitude
`origin_lat`	The origin latitude
`bearing`	The angle in degrees relative to due north
`gc_dist`	The great circle distance in (km)

# one degree longitude is approximately 111km at the equator. Therefore if we
# travel 111km due east from the coordinate {0,0} we can verify that we have
# moved approximately 1 degree longitude and zero degrees latitude
bearing_to_lonlat(0, 0, 90, 111)