Add test case cover for gen_tile_macro command

[KelvinChung2000]

For 1. I have written something that should cover that, but it doesn't seem to be doing so atm. I need to add more test case to cover that.

FABulous/fabulous/fabulous_cli/fabulous_cli.py

Lines 1327 to 1329 in 7d11f8a

	if not args.tile:
	logger.error("Tile name must be specified")
	return

So this could also be a problem from the upstream cmd2. As that looks like it is hitting something from that side before even hitting our logic.

Originally posted by @KelvinChung2000 in #649 (comment)