Run license activation in an empty directory (#285)

dist/steps/return_license.sh

@@ -1,5 +1,9 @@
 #!/usr/bin/env bash
 
+# Run in ACTIVATE_LICENSE_PATH directory
+echo "Changing to \"$ACTIVATE_LICENSE_PATH\" directory."
+pushd "$ACTIVATE_LICENSE_PATH"
+
 if [[ -n "$UNITY_SERIAL" ]]; then
   #
   # PROFESSIONAL (SERIAL) LICENSE MODE
@@ -11,3 +15,6 @@ if [[ -n "$UNITY_SERIAL" ]]; then
     -quit \
     -returnlicense
 fi
+
+# Return to previous working directory
+popd