Add basic test in main_test and check it passes with 'go test'

examples/testing/main_test.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"testing"
+)
+
+func IntMin(a, b int) int {
+	if a < b {
+		return a
+	} else {
+		return b
+	}
+}
+
+func TestIntMinBasic(t *testing.T) {
+	result := IntMin(2, -2)
+	if result != -2 {
+		t.Errorf("IntMin(2, -2) = %d; want -2", result)
+	}
+}