make whitespace handling more robust (prismatic-io#8)

* use eval to run shell command

* remove debug output

action.yml

@@ -140,6 +140,7 @@ runs:
       shell: bash
       run: |
         source $GITHUB_WORKSPACE/logger.sh
+
         if ! npm list -g @prismatic-io/prism &> /dev/null; then
           log $INFO "\U1F527 Prism CLI is not installed. Installing..."
           npm install --global @prismatic-io/prism
@@ -186,7 +187,7 @@ runs:
         fi
 
         log $INFO "Running command: $COMMAND"
-        OUTPUT=$($COMMAND 2>&1)
+        OUTPUT=$(eval "$COMMAND" 2>&1)
 
         if echo "$OUTPUT" | grep -q "Package signatures match, skipping publish"; then
           echo "PUBLISH_SKIPPED=true" >> $GITHUB_OUTPUT