Fixed up is_bundle_available?

Author: Kevin Smith

lib/cog/relay/tracker.ex

@@ -141,8 +141,12 @@ defmodule Cog.Relay.Tracker do
   """
   @spec is_bundle_available?(t, relay_id, bundle_name, version) :: boolean()
   def is_bundle_available?(tracker, relay, bundle_name, bundle_version) do
-    {_all_relays, available_relays} = relays(tracker, bundle_name, bundle_version)
-    Enum.member?(available_relays, relay)
+    case relays(tracker, bundle_name, bundle_version) do
+      {:ok, available_relays} ->
+        Enum.member?(available_relays, relay)
+      _ ->
+        false
+    end
   end
 
   defp in_tracker?(tracker, relay_id) do