Include contributors section in release notes only if there is at least one contributor

Author: Jericho

src/GitReleaseManager.Core/Templates/default/contributors.sbn

@@ -6,5 +6,4 @@ __Contributors__
 
 {{ for contributor in contributors.items
     include 'contributor-details'
-end }}
-
+end }}

src/GitReleaseManager.Core/Templates/default/index.sbn

@@ -4,7 +4,9 @@
         include 'milestone'
     end
     include 'issues' | string.rstrip
-    include 'contributors'
+    if contributors.count > 0
+        include 'contributors'
+    end
     if template_kind == "CREATE"
         include 'create/footer'
     end