add comments for verifying custom menu

calDistance.go

-package main
-
-import "math"
-
-// haversin(θ) function
-func hsin(theta float64) float64 {
-	return math.Pow(math.Sin(theta/2), 2)
-}
-
-// Distance function returns the distance (in meters) between two points of
-//     a given longitude and latitude relatively accurately (using a spherical
-//     approximation of the Earth) through the Haversin Distance Formula for
-//     great arc distance on a sphere with accuracy for small distances
-//
-// point coordinates are supplied in degrees and converted into rad. in the func
-//
-// distance returned is METERS!!!!!!
-// http://en.wikipedia.org/wiki/Haversine_formula
-func Distance(lat1, lon1, lat2, lon2 float64) float64 {
-	// convert to radians
-	// must cast radius as float to multiply later
-	var la1, lo1, la2, lo2, r float64
-	la1 = lat1 * math.Pi / 180
-	lo1 = lon1 * math.Pi / 180
-	la2 = lat2 * math.Pi / 180
-	lo2 = lon2 * math.Pi / 180
-
-	r = 6378100 // Earth radius in METERS
-
-	// calculate
-	h := hsin(la2-la1) + math.Cos(la1)*math.Cos(la2)*hsin(lo2-lo1)
-
-	return 2 * r * math.Asin(math.Sqrt(h))
-}

customMenu_test.go

 func TestGetMenu(t *testing.T) {
 	SetupConfig()
 	CreateDefaultMenu()
+	//check menu from Wechat
 }