Use application/json as content-type/accepts
Use application/json as content-type/accepts

For most regular API requests (i.e. not data upload) use
"application/json" as the media type. It would have been possible to use
the `requests` library built-in `json` kwarg, but it would have required
a bit more messing with the API for `request_raw()`. Explicitly
declaring them seemed like a reasonable first step.

analyzere/analyzere-python,analyzere/analyzere-python