Remove ununsed development dependencies

Author: rcdexta

package.json

@@ -75,8 +75,6 @@
     "eslint-plugin-standard": "^3.0.1",
     "eventsource-polyfill": "^0.9.6",
     "extract-text-webpack-plugin": "^2.1.0",
-    "isparta": "^4.0.0",
-    "istanbul": "^1.1.0-alpha.1",
     "jest": "^21.0.1",
     "jest-cli": "^21.0.1",
     "jsdom": "^9.12.0",
@@ -87,10 +85,8 @@
     "react-addons-test-utils": "^15.5.1",
     "react-dom": "^16.2.0",
     "react-test-renderer": "^15.4.2",
-    "rimraf": "^2.6.1",
     "sass-loader": "^6.0.6",
     "semantic-release": "^6.3.6",
-    "sinon": "^2.3.2",
     "style-loader": "^0.18.2",
     "webpack": "^3.0.0"
   },