fix for header's Content-Type:"strategic merge patch" for patch operation's.

[karthikkondapally]

fix for issue #127
tried to handle it according to doc https://github.com/kubernetes/community/blob/master/contributors/devel/api-conventions.md#patch-operations and also based on similar fix in python client (kubernetes-client/python#187)
but i believe this is not complete fix, as Content-Type: application/merge-patch+json is never set for merge operation of JSONs.
is it possible to explicitly tell whether it is application/merge-patch+json just for patch calls?

[brendandburns]

@mbohlool I think that maybe this should be fixed in the OpenAPI/Code Generation?

[karthikkondapally]

closing the pull request as this has to be fixed else where (OpenAPI/Code Generation)

[mbohlool]

I am not sure about a fix in OpenAPI or code generations. This is a special case we handle it similarly in python client (by checking the type of provided object and change the content-type accordingly). If you guys have a suggestion on how to fix this in code generation, I would like to discuss it, otherwise we should check in something similar to this PR.

[karthikkondapally]

In OpenAPI 2.0, filter/selection based on content type in request header is not present (link to issue raised in open api git) may be another usecase but issue also.
But in OpenAPI 3.0 this feature/support has been added (link to requestbody).

but swagger(3.0.0.0) which supports OpenAPI 3.0 is still in development phase.

one blunt solution to generate individual functions with correct content type is by splitting the paths of rest end point. some thing like /strategicMergePatchDeploymentWithList, /patchDeployment and /mergePatchDeployment in specification.