feature: al agrupar release, mergear cambios en rama group

src/git_flow/command/release.py

@@ -55,9 +55,11 @@ class ReleaseCommand(Command):
             print("- " + commit)
 
         group = args.group
+        grouping = group is not None
 
-        if not group:
+        if not grouping:
             if self.confirm("¿Desea agrupar este release con otra rama?", False):
+                grouping = True
                 group = self.choice("Grupo release: ", Git.get_branches("release/" + next_env + "/"))
             else:
                 group = next_env
@@ -98,3 +100,6 @@ class ReleaseCommand(Command):
                 print="Deshaciendo cambios por conflictos"
             )
             raise GitFlowError("Error al realizar pasaje de cambios a rama objetivo")
+        elif grouping:
+            Git("switch", group).exec(print="Cambiando a rama objetivo")
+            Git("merge", next_branch, ff_only=True).exec(print="Mergeando cambios de la nueva rama")