chore(package): update react-dom to version 16.6.0

Closes #136

Author: greenkeeper[bot]

package.json

@@ -4,6 +4,6 @@
     "coffee-script": "1.12.7",
     "prop-types": "15.6.0",
     "react": "16.6.0",
-    "react-dom": "16.2.0"
+    "react-dom": "16.6.0"
   }
 }