upgrade dev react & react-dom (#399)

Author: shatvl

package.json

@@ -68,8 +68,8 @@
  "jest": "^24.7.0",
  "less": "^3.9.0",
  "less-loader": "^4.1.0",
- "react": "^16.12.0",
- "react-dom": "^16.12.0",
+ "react": "^17.0.2",
+ "react-dom": "^17.0.2",
  "react-hot-loader": "^4.6.5",
  "react-testing-library": "^6.0.4",
  "style-loader": "^0.23.1",