Update dependency enzyme to v3

Author: renovate[bot]

package.json

@@ -41,7 +41,7 @@
     "babel-preset-react": "^6.23.0",
     "babel-preset-stage-0": "^6.22.0",
     "coveralls": "^2.12.0",
-    "enzyme": "^2.7.1",
+    "enzyme": "^3.0.0",
     "eslint": "^3.17.1",
     "eslint-plugin-react": "^6.10.0",
     "jest-cli": "^19.0.2",