chore(package): update eslint-plugin-unicorn to version 7.0.0

Closes #7

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
     "eslint-plugin-prettier": "^2.1.2",
     "eslint-plugin-promise": "^3.5.0",
     "eslint-plugin-react": "^7.1.0",
-    "eslint-plugin-unicorn": "^3.0.0",
+    "eslint-plugin-unicorn": "^7.0.0",
     "express": "^4.16.2",
     "jest": "^22.0.3",
     "husky": "^0.14.1",