Merge pull request #720 from gstf/mobile-col-fix

Use col-md to match rest of form on mobile devices

flask_admin/templates/bootstrap3/admin/lib.html

@@ -145,7 +145,7 @@
 
 {% macro render_form_buttons(cancel_url, extra=None) %}
     <div class="form-group">
-      <div class="col-sm-offset-2 col-sm-10 submit-row">
+      <div class="col-md-offset-2 col-md-10 submit-row">
 	<input type="submit" class="btn btn-primary" value="{{ _gettext('Submit') }}" />
 	{% if extra %}
 	{{ extra }}