fix(package): update intersection-observer to version 0.9.0

Closes #7

Author: greenkeeper[bot]

package.json

@@ -3,7 +3,7 @@
   "version": "0.1.0",
   "private": true,
   "dependencies": {
-    "intersection-observer": "^0.5.0",
+    "intersection-observer": "^0.9.0",
     "lorem-ipsum": "^1.0.6",
     "react": "^16.4.2",
     "react-dom": "^16.4.2",