Add ability to upload files within http forms.

[serhiibuniak-okta]

Note: buffered file can't be saved within vcr cassettes, thus integration test is marked for skipping. I work on solution

[bretterer]

This seems to be a major breaking change, updating the create_request method. Is that correct?

[serhiibuniak-okta]

This seems to be a major breaking change, updating the create_request method. Is that correct?

Yes, that would be a breaking change, although it doesn't brake existing functionality. This change might break the client code if somebody creates requests manually, thus we can update major version if this solution is accepted.

[bretterer]

This is a breaking change and needs to be called out when PR into master is made.