title: Support for the experimental syntax 'classProperties' isn't currently enabled
body: <p>While I was setting up React within Django project I came across this error</p>
  
  <p>ModuleBuildError in 
              Module build failed (from ./node_modules/babel-loader/lib/index.js):
      SyntaxError: C:\Users\1Sun\Cebula3\cebula_react\assets\js\index.js: Support 
      for the experimental syntax 'classProperties' isn't currently enabled (17:9):</p>
  
  <pre><code>  15 | 
    16 | class BodyPartWrapper extends Component {
  &gt; 17 |   state = {
       |         ^
    18 | 
    19 |   }
    20 | 
  
  Add @babel/plugin-proposal-class-properties (https://git.io/vb4SL) to the 
  'plugins' section of your Babel config to enable transformation.
  </code></pre>
  
  <p>So, I installed @babel/plugin-proposal-class-properties and put this in babelrc </p>
  
  <p><strong>package.json</strong></p>
  
  <pre><code>{
    "name": "cebula_react",
    "version": "1.0.0",
    "description": "",
    "main": "index.js",
    "scripts": {
      "start": "webpack-dev-server --config ./webpack.config.js --mode development",
      "test": "echo \"Error: no test specified\" &amp;&amp; exit 1",
      "build": "webpack --config prod.config.js"
    },
    "keywords": [],
    "author": "",
    "license": "ISC",
    "babel": {
      "presets": [
        "@babel/preset-env",
        "@babel/preset-react"
      ]
    },
    "devDependencies": {
      "@babel/cli": "^7.0.0",
      "@babel/core": "^7.0.0",
      "@babel/plugin-proposal-class-properties": "^7.0.0",
      "@babel/preset-env": "^7.0.0",
      "@babel/preset-react": "^7.0.0",
      "babel-loader": "^8.0.2",
      "babel-plugin-transform-class-properties": "^6.24.1",
      "react-hot-loader": "^4.3.6",
      "webpack": "^4.17.2",
      "webpack-bundle-tracker": "^0.3.0",
      "webpack-cli": "^3.1.0",
      "webpack-dev-server": "^3.1.8"
    },
    "dependencies": {
      "react": "^16.5.0",
      "react-dom": "^16.5.0"
    }
  }
  </code></pre>
  
  <p><strong>babelrc</strong></p>
  
  <pre><code>{
    "presets": [
      "@babel/preset-env",
      "@babel/preset-react"
    ],
    "plugins": [
      "@babel/plugin-proposal-class-properties"
    ]
  }
  </code></pre>
  
  <p>However the error is still existed, What is the problem??</p>