console in grumlin-0.20.0

- old
+ new

@@ -5,9 +5,11 @@
 require "grumlin"
 
 require "irb"
 require "irb/completion"
 
+require "dead_end"
+
 Grumlin.configure do |config|
   config.url = ENV.fetch("GREMLIN_URL", "ws://localhost:8182/gremlin")
 end
 
 Async do