Update the code coverage rate to 80% (#63)

Update the code coverage rate to 80%

azure-pipelines.yml

@@ -9,7 +9,7 @@ trigger:
       - '*'
 
 variables:
-  DIFF_COVER_CHECK_THRESHOLD: 70
+  DIFF_COVER_CHECK_THRESHOLD: 80
   DIFF_COVER_ENABLE: 'true'
   DIFF_COVER_WORKING_DIRECTORY: $(System.DefaultWorkingDirectory)
 
@@ -33,11 +33,11 @@ steps:
 - script: |
     set -xe
     sudo apt-get -y purge libhiredis-dev libnl-3-dev libnl-route-3-dev
+    sudo apt install -y libhiredis0.14
     sudo dpkg -i libnl-3-200_*.deb
     sudo dpkg -i libnl-genl-3-200_*.deb
     sudo dpkg -i libnl-route-3-200_*.deb
     sudo dpkg -i libnl-nf-3-200_*.deb
-    sudo dpkg -i libhiredis0.14_*.deb
     sudo dpkg -i libyang_1.*.deb
     sudo dpkg -i libswsscommon_1.0.0_amd64.deb
     sudo dpkg -i python3-swsscommon_1.0.0_amd64.deb