Use mamba in place of conda for unix CI jobs

Author: gsakkis

.github/workflows/build.yml

@@ -25,22 +25,20 @@ jobs:
     - uses: actions/checkout@v2
     - uses: conda-incubator/setup-miniconda@v2
       with:
-        auto-update-conda: true
         python-version: ${{ matrix.python-version }}
+        mamba-version: "*"
         activate-environment: test
         channels: conda-forge
         auto-activate-base: false
 
     - name: Linux dependencies
       if: matrix.os == 'ubuntu-latest'
       shell: bash -l {0}
-      run: |
-          sudo apt-get install gcc-multilib -y
+      run: sudo apt-get install gcc-multilib -y
 
     - name: Dependencies
       shell: bash -l {0}
-      run: |
-        conda install --yes --quiet -c conda-forge scikit-build numpy python=${{ matrix.python-version }} cython pdal pytest
+      run: mamba install --yes --quiet -c conda-forge scikit-build numpy python=${{ matrix.python-version }} cython pdal pytest
 
     - name: Install
       shell: bash -l {0}
@@ -74,7 +72,6 @@ jobs:
     - uses: conda-incubator/setup-miniconda@v2
       with:
         channels: conda-forge
-        auto-update-conda: true
         python-version: ${{ matrix.python-version }}
 
     - name: Dependencies
@@ -119,13 +116,12 @@ jobs:
     - uses: conda-incubator/setup-miniconda@v2
       with:
         channels: conda-forge
-        auto-update-conda: true
         python-version: ${{ matrix.python-version }}
+        mamba-version: "*"
 
     - name: Dependencies
       shell: bash -l {0}
-      run: |
-        conda install --yes --quiet -c conda-forge scikit-build numpy python=${{ matrix.python-version }} cython pdal pytest
+      run: mamba install --yes --quiet -c conda-forge scikit-build numpy python=${{ matrix.python-version }} cython pdal pytest
 
     - name: sdist
       shell: bash -l {0}