fix(transformer): prefer explicit config over auto-detected schema

for example, prefer responses confgured in @ApiOperation instead of
what's detected from return type of the controller function

fixes: #1420

lib/swagger-transformer.ts

@@ -17,8 +17,8 @@ export class SwaggerTransformer {
       );
       return mapValues(keyByMethod, (route: any) => {
         return {
-          ...omit(route.root, ['method', 'path']),
           ...omit(route, 'root')
+          ...omit(route.root, ['method', 'path']),
         };
       });
     });