Append the buildpack artifacts and droplet upload uri to UploadAction

[#80393104]
Report metrics after claiming the task

[#81308656]
Use API for desiring tasks, rather than BBS

Still need to handle API Basic Auth
[#79618154]

Signed-off-by: Jacques Chester <jchester@pivotal.io>
apiClient -> ccClient in outbox

[#79618154]
Use API in outbox instead of BBS [#79618154]

Signed-off-by: Max Brunsfeld <mbrunsfeld@pivotal.io>
Rename API Client to CC Client [#79618154]

Signed-off-by: Max Brunsfeld <mbrunsfeld@pivotal.io>
Rename API Client to Diego API Client [#79618154]

Signed-off-by: Max Brunsfeld <mbrunsfeld@pivotal.io>
Pass stager's URL as callback url on created tasks

[#79618154]

Signed-off-by: Max Brunsfeld <mbrunsfeld@pivotal.io>