Bump react-addons-test-utils version

package.json

@@ -52,7 +52,7 @@
     "react": "^15.4.0",
     "react-addons-perf": "0.14.8",
     "react-addons-shallow-compare": "0.14.8",
-    "react-addons-test-utils": "0.14.8",
+    "react-addons-test-utils": "^15.4.0",
     "react-collapse": "2.3.1",
     "react-dom": "^15.4.0",
     "react-height": "^2.0.0",
@@ -90,6 +90,7 @@
     "css-loader": "0.22.0",
     "deep-extend": "^0.4.1",
     "deepmerge": "^1.3.2",
+    "enzyme": "^2.7.1",
     "eslint": "^2.13.1",
     "eslint-plugin-react": "^4.3.0",
     "extract-text-webpack-plugin": "0.8.2",