Migrate python storage to webserver

The current storage is implemented in python and spawns processes for handling concurrent file operations. This is suboptimal since python uses global interpreter lock and does not allow dynamic profiling and inspecting dynamic resource usage.

The task is to implement rest API in go webserver that would allow uploading and downloading storage files via http.

Example. Download/upload binary artifact to remote storage

1. Write unittest api_test.go
2. Implement handlers and register URL for download/upload
3. Make sure that the test passes