Fail when bad host uri is used

[fuzzball81]

As a user I would like api calls to fail with an exception if an dlrn instance can't be reached. Currently when an api request is made to a bad host uri or when their is not a dlrn instance to contact, the request will just keep timing out every 30 seconds instead of failing with an exception that can be handled.

Example:

params = dlrnapi_client.Params()
client = dlrnapi_client.ApiClient(host='https://bad-server.org/api-centos-bad')                                                                                                                 
api_instance = dlrnapi_client.DefaultApi(api_client=client)
data = api_instance.api_last_tested_repo_get(params)