add error message for package.json not found

updates.js

@@ -132,6 +132,9 @@ if (args.file) {
   }
 } else {
   packageFile = require("find-up").sync("package.json");
+  if (!packageFile) {
+    finish(new Error(`Unable to find package.json in this or any parent directories`));
+  }
 }
 
 let dependencyTypes;