Update build.yml

Author: torresc24

.github/workflows/build.yml

@@ -15,22 +15,26 @@ jobs:
         python-version: [3.4, 3.5, 3.6.8]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v1
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
-          pip install --upgrade pip
+          python -m pip install --upgrade pip
+          python -m pip install sphinx
           pip install virtualenv==20.0.1
-          pip install tox tox-gh-actions 
+      - name: Install tox
+        if: python-version != 3.4 
+        run: pip install tox tox-gh-actions
       - name: Test with tox
+        if: python-version != 3.4
         run: |
           tox
           pip install -e .
       - name: Before deploy 
         run: |
           pip install -e .
           pip install --upgrade setuptools
-          make docs 
+          make docs