Update dependencies to enable Greenkeeper 🌴 (#1)

* chore(package): update dependencies

* docs(readme): add Greenkeeper badge

* reorder

packages/keyv-mongo/README.md

@@ -1,5 +1,7 @@
 # keyv-mongo
 
+[![Greenkeeper badge](https://badges.greenkeeper.io/lukechilds/keyv-mongo.svg)](https://greenkeeper.io/)
+
 > MongoDB storage adapter for Keyv
 
 [![Build Status](https://travis-ci.org/lukechilds/keyv-mongo.svg?branch=master)](https://travis-ci.org/lukechilds/keyv-mongo)

packages/keyv-mongo/package.json

@@ -42,12 +42,12 @@
     "pify": "^3.0.0"
   },
   "devDependencies": {
-    "ava": "^0.19.1",
+    "ava": "^0.21.0",
     "coveralls": "^2.13.1",
     "eslint-config-xo-lukechilds": "^1.0.0",
     "keyv": "*",
     "keyv-test-suite": "*",
-    "nyc": "^10.3.2",
+    "nyc": "^11.0.3",
     "requireable": "^1.0.1",
     "xo": "^0.19.0"
   }