Migrate integration test for universe/go

Signed-off-by: Solomon Hykes <solomon@dagger.io>

stdlib/go/testdata/go.mod

@@ -0,0 +1,3 @@
+module main
+
+go 1.14

stdlib/go/testdata/main.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("hello world")
+}