Remove prop-types from devDependency

Author: Daniel Schmidt

package.json

@@ -85,7 +85,6 @@
     "jest": "^21.2.1",
     "lint-staged": "^4.2.3",
     "prettier": "^1.7.4",
-    "prop-types": "^15.6.0",
     "react": "^16.0.0",
     "react-dom": "^16.0.0",
     "react-test-renderer": "^16.0.0"