chore(package): update enzyme to version 3.7.0

Closes #14

Author: greenkeeper[bot]

package.json

@@ -62,7 +62,7 @@
     "babel-polyfill": "^6.20.0",
     "babel-preset-react-native": "^1.9.0",
     "babel-register": "^6.18.0",
-    "enzyme": "^2.7.0",
+    "enzyme": "^3.7.0",
     "eslint": "^3.13.1",
     "eslint-config-airbnb": "^14.0.0",
     "eslint-plugin-import": "^2.2.0",