Optimized Dockerfile for react app

Author: callicoder

polling-app-client/src/constants/index.js

@@ -1,5 +1,4 @@
-export const API_BASE_URL = 'http://localhost:8080/api';
-//export const API_BASE_URL = '/api';
+export const API_BASE_URL = process.env.REACT_APP_API_BASE_URL || 'http://localhost:8080/api';
 export const ACCESS_TOKEN = 'accessToken';
 
 export const POLL_LIST_SIZE = 30;