Remove unused mustache templates

app/views/signed_form.mustache

Index: app/views/signed_form.mustache
diff --git a/app/views/signed_form.mustache b/app/views/signed_form.mustache
deleted file mode 100644
index 3d6926cbd78929d7857eece4fe3c01e187a5c37f..0000000000000000000000000000000000000000
--- a/app/views/signed_form.mustache
+++ /dev/null
@@ -1,12 +0,0 @@
-{{! Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-    for details. All rights reserved. Use of this source code is governed by a
-    BSD-style license that can be found in the LICENSE file. }}
-
-<form method="POST" enctype="multipart/form-data" action="{{url}}">
-  {{#fields}}
-    {{#value}}<input type="hidden" name="{{key}}" value="{{value}}">{{/value}}
-  {{/fields}}
-
-  <input type="file" name="file">
-  <input type="submit" value="Upload">
-</form>