Handle HTTP Errors when making requests to external Adobe Connect endpoint

[hderms]

In Service#request we make an HTTP get request via client.get(). We handle the response returned via AdobeConnect::Response. I think it would be useful to catch HTTP Errors before passing the information along to Response. In particular, we've encountered situations where an adobe connect server becomes unresponsive under extreme load, and being able to handle this reliably would be a huge boon.

In the event Net::HTTP encounters an error, the response returned will be of type Net::HTTPServerError. Perhaps we can raise an Adobe Connect specific exception in this case to enform any consumers of the API that they might need to retry the request.