Update tests.yml

Author: johnnynunez

.github/workflows/tests.yml

@@ -134,6 +134,7 @@ jobs:
         run: |
           wget -q -O - https://data.kitware.com/api/v1/file/hashsum/sha512/5d937e938f7b882a3a3e7941e68f8312d0898aaf2082e00003dd362b1ba70b98b0a08706a1be28e71652a6a0f1e66f89768b5eaa20e5a100592d5b3deefec3f0/download | tar zxf - -C ~/
       - name: Run tests
+        shel: bash
         run: |
           export PATH=~/castxml/bin:$PATH
           pytest tests