What is claimed is the ornamental design for a golf training device, as shown and described.
FIG. 1 is a perspective view of a golf training device, showing the new design;
FIG. 2 is an alternate perspective view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a left-side elevational view thereof, the right-side elevational view being a mirror image thereof;
FIG. 6 is a front elevational view thereof; and,
FIG. 7 is a rear elevational view thereof.
The broken lines showing a swinging golf club and ball in FIG. 1 are included for the purpose of illustrating the invention in use, and form no part of the claimed design.