Sort controllers so that builds are reproducible.

Ordering of controllers in routes.go and main.go is unstable in
successive runs of revel build.  This change will assure that the
ordering is stable.

harness/build.go

@@ -42,6 +42,10 @@ func Build(buildFlags ...string) (app *App, compileError *revel.Error) {
 		sourceInfo.InitImportPaths = append(sourceInfo.InitImportPaths, strings.Split(dbImportPath,",")...)
 	}
 
+	// Sort controllers so that file generation is reproducible
+	controllers := sourceInfo.ControllerSpecs()
+	sort.SliceStable(controllers, func(i, j int) bool { return controllers[i].String() < controllers[j].String() })
+
 	// Generate two source files.
 	templateArgs := map[string]interface{}{
 		"Controllers":    sourceInfo.ControllerSpecs(),