Update CI workflow

.github/workflows/ci.yml

@@ -51,10 +51,7 @@ jobs:
     - name: Install package and dependencies
       run: |
         python -m pip install --upgrade pip setuptools build
-        python -m pip install .[lint,test]
-    - name: Check types with mypy
-      run: |
-        mypy
+        python -m pip install .[test]
     - name: Test with pytest
       run: |
         pytest --cov=electrolytes