chore(package): update pouchdb to version 7.2.0

Closes #28

Author: greenkeeper[bot]

package.json

@@ -35,6 +35,6 @@
     "istanbul": "^0.4.5",
     "memdown": "^1.0.0",
     "mocha": "^3.2.0",
-    "pouchdb": "^6.0.0"
+    "pouchdb": "^7.2.0"
   }
 }