Fix AZP artifact names (#415)

* update pipeline.yaml

Author: matmerr

.pipelines/pipeline.yaml

@@ -50,7 +50,8 @@ stages:
 
           - script: |
               echo "##vso[task.setvariable variable=CommitHash;isOutput=true]$(git rev-parse HEAD)"
-              BRANCH=$(git rev-parse --abbrev-ref HEAD)
+              export BRANCH=$(Build.SourceBranchName)
+              echo Building branch $BRANCH from $(Build.SourceBranch) 
               if [[ "$BRANCH" == "master" ]]; then
                 echo "##vso[task.setvariable variable=Tag;isOutput=true]$(git describe --tags --abbrev=0)"
                 echo "Set tag to $(git describe --tags --abbrev=0)"