chore(update dependencies):

Author: posva

package-lock.json

@@ -35,20 +35,20 @@
   },
   "homepage": "https://github.com/vuejs/vuefire#readme",
   "peerDependencies": {
-    "firebase": "^4.5.0"
+    "firebase": ">=4.0.0"
   },
   "devDependencies": {
     "ava": "^0.23.0",
     "babel-plugin-istanbul": "^4.1.5",
-    "babel-preset-env": "^1.6.0",
+    "babel-preset-env": "^1.6.1",
     "babel-register": "^6.26.0",
-    "cross-env": "^5.0.5",
-    "cz-conventional-changelog": "^2.0.0",
-    "firebase": "^4.5.0",
+    "cross-env": "^5.1.1",
+    "cz-conventional-changelog": "^2.1.0",
+    "firebase": "^4.6.1",
     "mkdirp": "^0.5.1",
     "nyc": "^11.3.0",
-    "rollup": "^0.50.1",
-    "rollup-plugin-buble": "^0.16.0",
+    "rollup": "^0.51.1",
+    "rollup-plugin-buble": "^0.17.0",
     "uglify-js": "^3.1.8",
     "vue": "^2.5.3"
   },