Specify Mono for MacOS build

Author: JoeRobich

.pipelines/init.yml

@@ -44,7 +44,7 @@ steps:
       arguments: install tools/packages.config -ExcludeVersion -OutputDirectory tools
   - ${{ if ne(parameters.MonoVersion, '') }}:
       - script: |
-          curl -o mono.pkg https://download.mono-project.com/archive/$MONO_VERSION/macos-10-universal/MonoFramework-MDK-$MONO_VERSION.182.macos10.xamarin.universal.pkg
+          curl -o mono.pkg https://download.mono-project.com/archive/$MONO_VERSION/macos-10-universal/MonoFramework-MDK-$MONO_VERSION.206.macos10.xamarin.universal.pkg
           sudo installer -pkg mono.pkg -target /
           sudo cp -rf /Library/Frameworks/Mono.framework/Versions/$MONO_VERSION/ /Library/Frameworks/Mono.framework/Versions/Current/
           MONOPREFIX=/Library/Frameworks/Mono.framework/Versions/$MONO_VERSION

azure-pipelines.yml

@@ -21,7 +21,7 @@ variables:
   CakeVersion: "4.2.0"
   NuGetVersion: "6.5.0"
   GitVersionVersion: "5.0.1"
-  MonoVersion: ""
+  MonoVersion: "6.12.0"
   Coverage: "$(Agent.BuildDirectory)/c"
   VstsCoverage: "$(Coverage)"
   Artifacts: $(Build.SourcesDirectory)/artifacts/
@@ -100,6 +100,7 @@ stages:
               CakeVersion: $(CakeVersion)
               DotNetVersion: $(DotNetVersion)
               NuGetVersion: $(NuGetVersion)
+              MonoVersion: $(MonoVersion)
           - script: |
               echo $PATH
               chmod 755 ./build.sh