Claranet-tfwrapper

UPDATES:

- TER-28: Add support for Azure stacks.

UPDATES:

- TER-188: Use AWS profile as part of the pickle session cache filename.
- TER-190: Initialize returncode.
- TER-192: Update `README.md`.

UPDATES:

- TER-176: Add license file.

NOTES:

- Terraform subcommands error codes are now correctly returned.
- Terraform 0.10.x is now supported with centralized provider caching.

UPDATES:

- TER-46: Update requirements.txt to be compatible with Python 3.6.
- TER-132: Enable provider caching.
- TER-135: Remove unnecessary reference to role.
- TER-139: Return Terraform's return code.
- TER-174: Make sure that we pass pycodestyle check.

NOTES:

- Wrapper messages are now outputted to `stderr`

UPDATES:

- TER-104: Output wrapper messages on `stderr`
- TER-105: Catch some usual exceptions

UPDATES:

- TER-99: Update terraform subcommands.