removed unused capistrano file

lib/leap_cli/lib_ext/capistrano_connections.rb

-module Capistrano
-  class Configuration
-    module Connections
-      def failed!(server)
-        @failure_callback.call(server) if @failure_callback
-        Thread.current[:failed_sessions] << server
-      end
-
-      def call_on_failure(&block)
-        @failure_callback = block
-      end
-    end
-  end
-end
-
-