Add test command to tinygo (#243)

* Add test command to tinygo

tests/tinygotest/main.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	Thing()
+	fmt.Println("normal main")
+}
+
+func Thing() {
+	fmt.Println("THING")
+}

tests/tinygotest/main_test.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"testing" // This is the tinygo testing package
+)
+
+func TestFail1(t *testing.T) {
+	t.Error("TestFail1 failed because of stuff and things")
+}
+
+func TestFail2(t *testing.T) {
+	t.Error("TestFail2 failed for reasons")
+}
+
+func TestPass(t *testing.T) {
+}