get application APIs

[noahdietz]

• updated vendor to remove k8s dep && update the aws-sdk-go dep
• improved responses of application retrieval APIs

Fixes #75

[whitlockjc]

LGTM

[noahdietz]

Samples:

$ shipyardctl get application -o noahmdietz2 -n example
[{"revision":["noahmdietz2/example:6"]},{"revision":["noahmdietz2/example:5"]},{"revision":["noahmdietz2/example:4"]},{"revision":["noahmdietz2/example:3"]},{"revision":["noahmdietz2/example:2"]},{"revision":["noahmdietz2/example:1"]}]
----
$ shipyardctl get application -o noahmdietz2 -n example:3
{"created":"2017-01-20T00:17:07Z","revision":["noahmdietz2/example:3"],"imageId":"sha256:ef82c56e4d2d3564f8f71c13442aff5c5f6bb1dca339afd3252ba8ce78aa72ea"}