pin python version at 3.8 until I test 3.9.0

Author: craigbarratt

.github/workflows/validate.yml

@@ -18,7 +18,7 @@ jobs:
       - uses: "actions/checkout@v2"
       - uses: "actions/setup-python@v1"
         with:
-          python-version: "3.x"
+          python-version: "3.8"
       - run: python3 -m pip install black
       - run: black .
 
@@ -29,7 +29,7 @@ jobs:
       - uses: "actions/checkout@v2"
       - uses: "actions/setup-python@v1"
         with:
-          python-version: "3.x"
+          python-version: "3.8"
       - run: python3 -m pip install -r tests/requirements_test.txt
       - run: pytest --cov=custom_components
 
@@ -40,6 +40,6 @@ jobs:
       - uses: "actions/checkout@v2"
       - uses: "actions/setup-python@v1"
         with:
-          python-version: "3.x"
+          python-version: "3.8"
       - run: python3 -m pip install -r tests/requirements_test.txt
       - run: pylint custom_components/pyscript/*.py tests/*.py