Merge pull request #37 from DoubleML/m-ci-build-pkg

fixed the setting of env var on github actions

Author: MalteKurz

.github/workflows/deploy_docu.yml

@@ -89,7 +89,7 @@ jobs:
         SSH: true
 
     - name: Get tag
-      run: echo ::set-env name=RELEASE_VERSION::$(echo ${GITHUB_REF:10})
+      run: echo RELEASE_VERSION=${GITHUB_REF:10} >> $GITHUB_ENV
 
     - name: Deploy to version
       if: ${{ github.event_name == 'release' }}