Auxiliary HTTP file test server

Available paths:

/help
this message.

/upload
takes any file to be uploaded and deletes the file after upload
returns JSON:
  e.g.,
  {
    "request method": "POST",
    "filename": "example.zip",
    "size": 332464615,
    "starttime": "2018-01-25T13:37:28.515Z",
    "endtime": "2018-01-25T13:37:29.948Z",
    "duration": 1433
  }

/download (return code 200)
  /gzip
    /{number of bytes to be received}
    number of bytes requested to be sent
  /nogzip data should be received
    /{number of bytes to be received}
    number of bytes requested to be sent as gzip avoiding data

returns:
  a data file