Fix the CI build error by downloading the tbb binaries
diff --git a/.github/workflows/macOS.yaml b/.github/workflows/macOS.yaml
index d38ce32..6b5fde2 100644
--- a/.github/workflows/macOS.yaml
+++ b/.github/workflows/macOS.yaml
@@ -33,6 +33,10 @@
       - name: install-build-dependencies
         run: |
          brew install protobuf swig opencv glog lmdb numpy
+         wget https://github.com/oneapi-src/oneTBB/releases/download/v2020.1/tbb-2020.1-mac.tgz 
+         mkdir /tmp/tbb
+         tar zxvf tbb-2020.1-mac.tgz -C /tmp/tbb --strip-components=1
+         mv /tmp/tbb/lib/lib* /usr/local/lib/
          pip3 install numpy && wget https://github.com/oneapi-src/oneDNN/releases/download/v1.2/dnnl_mac_1.2.0_cpu_tbb.tgz -P /tmp
          tar zxf /tmp/dnnl_mac_1.2.0_cpu_tbb.tgz -C /tmp
       - name: configure
@@ -48,7 +52,6 @@
           LD_LIBRARY_PATH: /usr/local/opt/openblas/lib:/tmp/dnnl_mac_1.2.0_cpu_tbb/lib:$LD_LIBRARY_PATH
       - name: C++ test
         run: |
-         brew install tbb
          install_name_tool -change libdnnl.1.dylib /tmp/dnnl_mac_1.2.0_cpu_tbb/lib/libdnnl.1.dylib /Users/runner/work/singa/singa/build/lib/libsinga.dylib
          install_name_tool -change libdnnl.1.dylib /tmp/dnnl_mac_1.2.0_cpu_tbb/lib/libdnnl.1.dylib build/bin/test_singa
          build/bin/test_singa