Use `req.params.id` instead of `req.query.id`.

In update and destroy middleware.
Merge pull request #13 from lemonde/query-to-params

Use req.params instead of req.query
Merge pull request #15 from lemonde/withrelated-fix

Don't format withRelated
Add error utility.
Fix bug and test in checkExist middleware.
Default status code to 400 in error utility.
Use generated errors in middlewares.