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
If I return a value, chaining doesn't work - the resolve callback on the next function doesn't get called.