fixed linting errors on packages/medusa/src/services/user.js #531 (#543)

* fixed linting errors on packages/medusa/src/services/user.js #531

* fix: resolving a few issues as raised in the PR, issue: #531

Co-authored-by: Sergiy Fomin <sergiy.fomin@sourcedgroup.com>

jest-transformer.js

@@ -1,4 +1,4 @@
-const babelPreset = require(`babel-preset-medusa-package`)()
+const babelPreset = require(`babel-preset-medusa-package`)();
 module.exports = require(`babel-jest`).createTransformer({
   ...babelPreset,
-})
+});