Try not upgrading pip

Author: brandon-rhodes

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
       shell: bash
       run: |
         source ./V/bin/activate
-        python -m pip install --upgrade pip
+        # python -m pip install --upgrade pip
         pip install astropy==3.0.1 docutils==0.17.1 matplotlib==3.3.0 numpy==1.15.4 pandas==1.0.0 pyflakes scipy==1.2.2 sphinx==1.7.2 spktype21
 
     - name: Install Skyfield