Ansible-tower-cli

This would be the first release of Tower CLI 3.1.x LTS versions for API v1.
* Follow up 3.1.6 by duplicating `exceptions.py` to support `import tower_cli.utils.exceptions` syntax.

* Fix a usage compatibility issue for Ansible Tower modules.

- Major code base file structure refactor. Now all click-related logics are moved to `tower_cli/cli/` directory, and `exceptions.py` as well as `compat.py` are moved out of utils directory into base directory.
- Categorize help text options for resource action commands (like `update`) to increase readability.
- Behavior change of workflow schema command. Now schema will both create new nodes and delete existing nodes when needed to make the resulting workflow topology exactly the same as described in schema file.
- Add command `job_template callback` to enable conducting provisioning callback via Tower CLI.
- Add new format option to just echo id.
- Expand some resource fields, including hipchat rooms for notification template and allow_simultaneous for job templates.
- Lookup related inventory sources with "starts with" logic if its name is not fully qualified.
- Fixed a python 3.5 compatibility issue that causes job monitor traceback.
- Minor typo and help text updates.

- Support resource copy subcommand.
- Support auth-token-based authentication for Tower CLI requests.
- Support managing workflow roles, labels and notifications via Tower CLI.
- Several fixes on RPM spec file.
- Name change from 'foreman' to 'satellite6' in credential kind choices.
- Fixed a bug where creating job templates with --extra-vars did not work after
3.1.0 upgrade.
- Fixed traceback when launching job with --use-job-endpoint.
- Enhanced json library usage to prevent traceback when using earlier python 2.6
versions.
- Prevent throwing unnecessary warning when reading from global configuration file.

- Fixed a bug where extra_vars were dropped in some commands.

- Fixed a bug where global flags are not added to some commands.