DCR: Target Python 3.7 instead of Python 3.6 for BotBuilder-Python

[stevengum]

Proposed change

Target Python 3.7 instead of Python 3.6 for BotBuilder-Python

Benefits:

1. Performance Optimizations
2. typing module improvements:
   • PEP 563: Postponed Evaluation of Annotations
   • Addresses forward hints (referencing names that haven't yet been defined); good-bye string literals! (PEP 563)
   • Core support for typing module (Much faster) (PEP 560)
3. asyncio module improvements:
   • much simpler to run asyncio code in synchronous code (asyncio.run(coro))
   • asyncio is faster

Component Impact

No meaningful code changes in our Python SDK

• In classes with fluent methods we'll use from __future__ import annotations to make use of PEP 563

Customer Impact

• Users will need to use 3.7 or they'll get SyntaxErrors from the __future__ import

Tracking Status

Python SDK

• PR
• Merged

[dcr]

[stevengum]

Other packages that support Python 3.7:

• Spacy ≥ 2.0.12
• NumPy ≥ 1.15.0
• TensorFlow ≥ 1.13.1

Packages that do not yet support Python 3.7:

TensorFlow (Expected version is 1.13, but may be out in 1.12, it appears the last required dependency before 3.7 support was updated in the last week)