Dcos-shakedown

Features:

- bumped `dcoscli` version to `0.5.5`

Features:

- bumped `dcoscli` version to `0.5.4`
- better attach error handling
- move from pip to pip3

Features:

- bumped `dcoscli` version to `0.5.3`

Fixes:

- use `timeout_sec` in `install_package()`
- return service name in `_get_service_name()`
- `wait_for()` should use `>=`, not `>`

Fixes:

- properly timeout with `time_wait()` in `wait_for_task_completion()`
- `time_wait` was not being imported in `dcos/master.py`
- use `get_tasks()` in `task_completed()`

Features:

- new methods for deploying Docker credentials
- `create_docker_credentials_file()`
- `distribute_docker_credentials_to_private_agents()`
- `prefetch_docker_image_on_private_agents()`
- added ability to query reservations
- `get_resources_by_role()`

Fixes:

- removed redundant filter in `get_task()`