The DeploymentServlet class provides in a list of versions available for a gateway and a stream
of data containing the DeploymentPackage (or fix package) for a specific gateway and version.
Responds to GET requests sent to this endpoint, the response depends on the requested path:
http://host/endpoint/gatewayid/versions/ returns a list of versions available for the specified gateway
http://host/endpoint/gatewayid/versions/x.y.z returns a deployment package stream for the specified gateway and version
The status code of the response can be one of the following:
HttpServletResponse.SC_BAD_REQUEST - If no gateway is specified or the request is malformed in a different way.