[ci] fix result color bar in the code coverage report (#196)

Signed-off-by: pettershao-ragilenetworks <pettershao@ragilenetworks.com>

azure-pipelines.yml

@@ -66,6 +66,7 @@ jobs:
 
       - script: |
           set -xe
+          sudo apt-get -y purge libhiredis-dev libnl-3-dev libnl-route-3-dev
           sudo dpkg -i libnl-3-200_*.deb
           sudo dpkg -i libnl-genl-3-200_*.deb
           sudo dpkg -i libnl-route-3-200_*.deb
@@ -92,6 +93,15 @@ jobs:
         workingDirectory: $(Pipeline.Workspace)/target/python-wheels/
         displayName: 'Install Python dependencies'
 
+      - script: |
+          set -ex
+          # Install .NET CORE
+          curl -sSL https://packages.microsoft.com/keys/microsoft.asc | sudo apt-key add -
+          sudo apt-add-repository https://packages.microsoft.com/debian/10/prod
+          sudo apt-get update
+          sudo apt-get install -y dotnet-sdk-5.0
+        displayName: "Install .NET CORE"
+
       # Python 2
       - ${{ if eq(project.python2, true) }}:
         - script: |