[#78] jwtMiddleware throws at startup

[ceciliaavila]

Fixes #78

Description

This PR fixes the error thrown by the jwtMiddleware when trying to get the authorization header from a request that does not include it. It adds a validation to return 405 Method not allowed responsense when the request is neither POST nor GET.
It also adds a new unit test to cover this case.

Detailed Changes

• Updated jwt-middleware to:
  • Include the new method validation.
  • Set the failed flag to true when it can't retrieve the authorization header. This will prevent the execution to continue after sending the response and the Cannot set headers after they are sent to the client error.
• Added a unit test in jwt-middleware.test and update the existing ones to assert the next function not being called.

Testing

The images illustrate the handling of an OPTIONS method request before the changes and the improvements implemented after the fix.