Improve error handler on the route level

[matheusfrancisco]

When I added a mock with an invalid body an exception happened, moclojer should be able to handle it and present some information like
{status: 500, body: "error"}

# The following schema is an example of how you can
# use the power of Moclojer to create your applications.
#
# Documentation: https://docs.moclojer.com
# Source Code: https://github.com/moclojer/moclojer

# This mock register route: GET /hello/:username
- endpoint:
    # Note: the method could be omitted because GET is the default
    method: GET
    path: /helloo/:username
    response:
      # Note: the status could be omitted because 200 is the default
      status: 200
      headers:
        Content-Type: application/json
      # Note: the body will receive the value passed in the url using the
      # :username placeholder
      body: |
        {{}
          "hello": "{{path-params.username}}!"
        }

[avelino]

will be implemented, I am closing this discussion and opening an issue for this problem with a proposed solution there #253