Aioalice

Fix 16 (17)

- support Yandex's side states (thx uburuntu 14)
- run actions on PR (thx uburuntu 15)

Maintenance update

+ use `safe_kwargs` for the root `AliceObject` - `AliceRequest` (closes 13)
+ update `attrs` version to 20.3.0 and update converter kwarg (closes 7)
+ get rid of all relative imports
+ run tests for different python versions
+ update how 'install requires' gets list of required packages - needed for new python versions

+ store raw json in models

Closes 9

There’s a backward-incompatible change in attrs 19.2.0 (2019-10-01): Removed deprecated Attribute attribute convert per scheduled removal on 2019/1.
https://www.attrs.org/en/stable/changelog.html