Bump isparta to v4 to fix test coverage

Author: ellbee

package.json

@@ -55,7 +55,7 @@
     "eslint-config-rackt": "1.1.0",
     "eslint-plugin-react": "^3.6.3",
     "expect": "^1.8.0",
-    "isparta": "^3.0.3",
+    "isparta": "4.0.0",
     "istanbul": "^0.3.17",
     "jsdom": "~5.4.3",
     "mocha": "^2.2.5",