fix(deps): update dependency eslint-plugin-flowtype to ^3.12.1 (#150)

Author: renovate[bot]

package-lock.json

@@ -44,7 +44,7 @@
     "@typescript-eslint/parser": "^1.12.0",
     "babel-eslint": "^10.0.2",
     "eslint-config-prettier": "^6.0.0",
-    "eslint-plugin-flowtype": "^3.11.1",
+    "eslint-plugin-flowtype": "^3.12.1",
     "eslint-plugin-import": "^2.18.0",
     "eslint-plugin-jsx-a11y": "6.2.3",
     "eslint-plugin-node": "^9.1.0",