Add admin interface to the document signatures app

mayan/apps/document_signatures/admin.py

@@ -0,0 +1,17 @@
+from __future__ import unicode_literals
+
+from django.contrib import admin
+
+from .models import DocumentVersionSignature
+
+
+class DocumentVersionSignatureAdmin(admin.ModelAdmin):
+    def has_detached_signature(self, instance):
+        return True if instance.signature_file else False
+
+    has_detached_signature.boolean = True
+    list_display = ('document_version', 'has_embedded_signature', 'has_detached_signature')
+    list_display_links = ('document_version',)
+
+
+admin.site.register(DocumentVersionSignature, DocumentVersionSignatureAdmin)