012_hands-on/04_solution/03/main.go : minor data coding error

[JESii]

In the data definitions for this solution, each region has its own title (e.g., 'Northern', 'Central', but the region values are all coded as 'southern' in the data structure. For example:

		region{
			Region: "Northern",
			Hotels: []hotel{
				hotel{
					Name:    "Hotel California",
					Address: "42 Sunset Boulevard",
					City:    "Los Angeles",
					Zip:     "95612",
					Region:  "southern",   <!-- s/b northern -->
				},
				hotel{
					Name:    "H",
					Address: "4",
					City:    "L",
					Zip:     "95612",
					Region:  "southern",  <!-- s/b northern -->
				},
			},
		},