Use bootstrap as executable name for playground environment: update function to get environment

mage_helpers/build.go

@@ -45,7 +45,7 @@ func Build(dir string, module string, isDebug bool) error {
 	fmt.Println(fmt.Sprintf("Building %v", handler))
 
 	outputFileName := handler
-	env := os.Getenv("ENVIRONMENT")
+	env := CurrentEnv()
 	fmt.Println("ENV:", env)
 	if env == "playground" {
 		fmt.Println("Using 'bootstrap' for output file name")