Fix step can not have uses and run

.github/workflows/ubuntu.yml

@@ -10,6 +10,7 @@ jobs:
         uses: actions/checkout@v2
         with:
           fetch-depth: 1
+      - name: Download openFrameworks and add ofxPiMapper
         run: mkdir .ofxPiMapper
         run: mv ./* .ofxPiMapper/
         run: wget ${OF_URL} --tries=10 --quiet