chore: remove react-dom from peerDependencies

Author: DongWoo Kim

package.json

@@ -20,8 +20,7 @@
   "license": "MIT",
   "browserslist": "last 2 versions, ie 9",
   "peerDependencies": {
-    "react": "^16.0.0",
-    "react-dom": "^16.0.0"
+    "react": "^16.0.0"
   },
   "devDependencies": {
     "@babel/core": "^7.2.2",