Now runs in Python3.3 thus is now truly compatible with ST3.

The code has been updated to run in Python 3.3, as required by ST3. That implied:

• Not using Data classes.
• Not using format strings.
• Minors in how SSL client is initialized.
• Avoidance of expansion of dicts and lists in arguments.
• Implementing .to_dict() as needed.
• Removed all type hints.
• Other minors.

Full Changelog: 1.1.0...1.2.0