fix yaml syntax issue (#132)

* fix yaml syntax issue

* Forgot to checkotu code

* try and fix the docs

.github/workflows/sphinx.yml

@@ -5,14 +5,16 @@ on:
 jobs:
   docs:
     runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
     - uses: conda-incubator/setup-miniconda@v2
       with:
         python-version: 3.9
         activate-environment: test
         channel-priority: true
         environment-file: devtools/conda-envs/espaloma.yaml
-        auto-activate-base: false
         use-mamba: true
+        mamba-version: "*"
 
     - name: Install package
       shell: bash -l {0}