Add support for python 3.8 (#25)

* feat: add support for python 3.8

* add poetry.lock

* fix: convert builtins to typing.Dict

* fix: use poetry 1.8.5 to publish

Author: furqaankhan

.github/workflows/pypi-publish.yaml

@@ -20,6 +20,8 @@ jobs:
           python-version: 3.8
       - name: Install Poetry
         uses: snok/install-poetry@v1
+        with:
+          version: 1.8.5
       - name: Compare tag and project version
         run: |
           if [ "v$(poetry version | cut -d' ' -f2)" != "${{ github.ref_name }}" ]; then echo "Version mismatch"; exit 1; fi