Add support for react 17

Closes #78.

Author: hoxu

package.json

@@ -57,7 +57,7 @@
     "webpack-dev-server": "^2.9.1"
   },
   "peerDependencies": {
-    "react": "^15.0.0 || ^16.0.0",
-    "react-dom": "^15.0.0 || ^16.0.0"
+    "react": "^15.0.0 || ^16.0.0 || ^17.0.0",
+    "react-dom": "^15.0.0 || ^16.0.0 || ^17.0.0"
   }
 }