fix(package): update react to version 16.12.0

Closes #7

Author: greenkeeper[bot]

package.json

@@ -15,7 +15,7 @@
   "license": "ISC",
   "dependencies": {
     "prop-types": "^15.5.10",
-    "react": "^15.6.1"
+    "react": "^16.12.0"
   },
   "devDependencies": {
     "@storybook/addon-info": "^3.1.9",