chore(package): update prettier to version 2.0.3

Closes #33

Author: greenkeeper[bot]

package.json

@@ -48,7 +48,7 @@
     "husky": "^3.0.0",
     "jest": "^24.8.0",
     "lint-staged": "^9.1.0",
-    "prettier": "^1.18.2",
+    "prettier": "^2.0.3",
     "rimraf": "^2.6.3",
     "semantic-release": "^15.13.20",
     "ts-jest": "^24.0.2",