Update tests-conda.yml

Update GitHub Actions workflow to use mamba for dependency management

.github/workflows/tests-conda.yml

@@ -24,33 +24,32 @@ jobs:
       uses: actions/setup-python@v2
       with:
         python-version: ${{ matrix.python-version }}
-    # Test matrix by printing the current Python version
     - name: Display Python version
       run: python -c "import sys; print(sys.version)"
     - name: Install dependencies
       shell: bash -l {0}
       run: |
         sudo apt-get update
-        # install openslide
         sudo apt-get install openslide-tools
-        # install pandoc for making documentation
         sudo apt-get install pandoc
     - name: Setup Miniconda
-      # You may pin to the exact commit or the version.
-      # uses: conda-incubator/setup-miniconda@f4c00b0ec69bdc87b1ab4972613558dd9f4f36f3
-      uses: conda-incubator/[email protected]
+      uses: conda-incubator/setup-miniconda@v2
       with:
-        add_pip_as_python_dependency: false
-        environment-file: environment.yml
+        auto-activate-base: false
         activate-environment: pathml
+        environment-file: environment.yml
+        mamba-version: "*"
         python-version: ${{ matrix.python-version }}
+    - name: Install dependencies with mamba
+      run: |
+        mamba env update --file environment.yml --name pathml
     - name: Conda info
       shell: bash -l {0}
       run: |
         conda info
         conda list
-    - name: pip install pathml
-      shell: bash -l {0}
+    - name: Install PathML
+      shell: bash -l {0}      
       run: pip install -e .
     - name: disk usage
       shell: bash -l {0}