Check which python is being used

Author: Joseph-Edwards

.github/workflows/tests.yml

@@ -99,6 +99,7 @@ jobs:
           echo "PKG_CONFIG_PATH=$MAMBA_ROOT_PREFIX/envs/libsemigroups/lib/pkgconfig:$MAMBA_ROOT_PREFIX/envs/libsemigroups/share/pkgconfig:/usr/local/lib/pkgconfig" >> $GITHUB_ENV
       - name: "Check Python version . . ."
         run: |
+          which python
           python --version
           pip --version
       - name: "Install make requirements (Mac only) . . ."