Boto34

Changed
- `SessionFactory` exposes underlying `session` and `service_name` as attributes
- Added docstrings to all methods
- Package no longer depends on `typing-extensions` explicitly

Fixed
- Removed usage of `Unpack` kwargs for `client`/`resource` for PyCharm support
- `boto34[aioboto3]` extra dependencies were incomplete
- Speed up `mypy` cold start by 30% by using a new file structure

Fixed
- Removed safe imports because they break typing
- Updated documentation

Changed
- `session.events` renamed to `session.eventbridge` to avoid shadowing underlying `Session` attribute

Fixed
- All unsafe imports included to `try-except` blocks
- Rebuilt with latest release of [mypy_boto3_builder](https://github.com/youtype/mypy_boto3_builder)

Added
- Yet another unofficial AWS SDK for Python

Removed
- Frustation Python community has while waiting for official type annotations from `boto3` team