Feature/math util (#22)

Development supports the math package

mathUtil/rand_example_test.go

@@ -0,0 +1,23 @@
+package mathUtil
+
+import "fmt"
+
+func ExampleRand() {
+	minInt := 1
+	maxInt := 100
+	res1 := Rand(minInt, maxInt)
+	if res1 >= 1 && res1 < 100 {
+		fmt.Println("ok")
+	}
+
+	minFloat := 1.0
+	maxFloat := 10.0
+	res2 := Rand(minFloat, maxFloat)
+	if res2 >= 1.0 && res2 < 10.0 {
+		fmt.Println("ok")
+	}
+
+	// Output:
+	// ok
+	// ok
+}