bel button with Save instead of Edit.

biscuit/apps/chronos/templates/chronos/edit_substitution.html

@@ -11,6 +11,6 @@
   <form method="post">
     {% csrf_token %}
     {% bootstrap_form edit_substitution_form %}
-    <input type="submit" value="Edit" />
+    <input type="submit" value="Save" />
   </form>
 {% endblock %}