TMSS-163: build in parallel

Docker/lofar-ci/Dockerfile_ci_mac

@@ -14,7 +14,7 @@ RUN echo "Installing Casacore..." && \
     mkdir /casacore/build/ && \
     cd /casacore/build/ && \
     cmake -DCMAKE_INSTALL_PREFIX=/opt/casacore -DBUILD_PYTHON3=ON -DBUILD_PYTHON=OFF -DPYTHON_EXECUTABLE=/usr/bin/python3 -DUSE_OPENMP=ON -DUSE_FFTW3=TRUE -DUSE_HDF5=ON -DCMAKE_BUILD_TYPE=Release .. && \
-    make && \
+    make -j 8 && \
     make install
 
 RUN echo "Installing Blitz++" && \
@@ -23,5 +23,5 @@ RUN echo "Installing Blitz++" && \
     mkdir -p /blitz/build && \
     cd /blitz/build && \
     cmake --prefix=/opt/blitz/ .. && \
-    make lib && \
+    make -j 8 lib && \
     make install
\ No newline at end of file