ci(rultor): squash instead of merging

Author: rafamizes

.rultor.yml

@@ -6,7 +6,7 @@ architect:
 assets:
   credentials.json: rafamizes/secret#assets/publishing/flutter/credentials.json
 merge:
-  # squash: true
+  squash: true
   rebase: true
   script: |
     flutter clean