add setup-python to actions

Author: yaythomas

.github/workflows/lint-test-build.yaml

@@ -21,6 +21,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
       - name: Run build pipeline for linting, testing & packaging verification.
         uses: pypyr/run-in-tox-action@master
         with:

.github/workflows/publish.yaml

@@ -9,6 +9,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
       - name: Run publish pipeline
         uses: pypyr/run-in-tox-action@master
         with:

.github/workflows/tag-release.yaml

@@ -18,6 +18,10 @@ jobs:
         with:
           # pull all tags also
           fetch-depth: 0
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
       - name: run tag pipeline.
         uses: pypyr/run-in-tox-action@master
         with: