bump eslint-plugin-prefer-let peer dep

Author: Kelly Selden

package.json

@@ -27,6 +27,6 @@
     "eslint-config-sane": "^1.0.0",
     "eslint-plugin-json-files": "^0.8.1",
     "eslint-plugin-node": "^11.1.0",
-    "eslint-plugin-prefer-let": "^1.0.0"
+    "eslint-plugin-prefer-let": "^1.1.0"
   }
 }