Incorrect Minor Version Check for Python 3.10. Fails >= 3.5 Check.

[Axe319]

https://github.com/vpython/vpython-jupyter/blob/d379190e847be8e5de4707932f304c35f83c7ee5/vpython/__init__.py#L20

The current implementation utilizes platform.python_version() and does a < '5' check against one character of the string. A more stable way to check would be to use sys.version_info.major and sys.version_info.minor respectively.