CI on macOS

Author: jeanbez

.github/workflows/macos.yml

@@ -24,7 +24,7 @@ jobs:
       - name: Build PDC
         run: |
           mkdir build && cd build
-          cmake ../ -DBUILD_MPI_TESTING=ON -DBUILD_SHARED_LIBS=ON -DBUILD_TESTING=ON -DPDC_ENABLE_MPI=ON -DCMAKE_C_COMPILER=mpicc
+          cmake ../ -DBUILD_MPI_TESTING=ON -DBUILD_SHARED_LIBS=ON -DBUILD_TESTING=ON -DPDC_ENABLE_MPI=ON -DCMAKE_C_COMPILER=mpicc -DCMAKE_POLICY_VERSION_MINIMUM=3.5
           make -j 2
 
       - name: Test PDC