Dcos-shakedown

Features:

- bumped `dcoscli` version to `0.4.15`

Fixes:

- `timeout_sec` passed through to `time_wait()` method

Features:

- SSH user (default `core`) can be specified on the command line
with `--ssh-user`
- new ZooKeeper `get_zk_node_data` function`

Fixes:

- `test_install_package_with_json_options` test is set to `xfail`
while it is being diagnosed

Features:

- test timeouts as defined by `--timeout` (or `timeout` in
`.shakedown` config) or `pytest.mark.timeout(n)` for
individual tests

Fixes:

- exit code is now returned for `run_dcos_command` calls
- fallbaack to `ssh-agent` if `.ssh/id_rsa` key fails
- `wait` predicate fixed from `1.1.9`
- use `service_name` rather than former ambiguous `app_id`

Fixes:

- fixing broken PyPI 1.1.9 release

Features:

- 'wait' functions and predicates, including `wait_for_task`,
`wait_for_task_property`, `wait_for_dns`, and `deployment_wait`
- new marathon methods for `deployment_wait`, `delete_all_apps`,
and `delete_all_apps_wait`
- support for passing a dict object containing JSON options to
`install_package` methods
- bumped `dcoscli` version to `0.4.14`

Fixes:

- pep8-compliance

Features:

- `--dcos-url` now defaults to pre-configured dcos-cli value
- `dcos_dns_lookup` method for resolving Mesos-DNS queries
- reworked network paritioning methods, including new utility
methods for `disconnected_agent`, `disconnected_master`,
`save_iptables`, `flush_all_rules`, `allow_all_traffic`, and
`iptable_rules`
- added `tox.ini` configuration file

Fixes:

- fixed documentation for `get_private_agents()`