Feat/evap upload svc

* made some small improvements to evaporate provider.
* added some meat to the upload service.
* added some basic tests for upload service, other parts of upload not yet tested.
* use of uuid and env in prefixing upload file name
* additional headers for content type, disposition, and privacy
Should this resolve to the upload, maybe? `return u`?

If you just don't want to do anything with the resolution, you can also use `undefined` as these parameters and they will be ignored.