Send request with out Content-Type header

[daniel-vergien-bdr]

We need to test requests with out the Content-Type Header to ensure correct error messages from our service.
According to an old stackoverflow post https://stackoverflow.com/questions/53650758/karate-automatically-sets-content-type-header this is a not so common need so we might need to provide a MR.

How should the syntax look like?

And header Content-Type = null

or

And without header Content-Type

[arodr25]

Hi, I am working on a team project in school and wanted to take a shot at this issue with my team, can I be allowed permission for this issue?

[ptrthomas]

@arodr25 consider permission granted, just follow the standard PR process: https://github.com/karatelabs/karate/blob/master/.github/CONTRIBUTING.md