Refactor Net::SSH spec helpers definition and usages

spec/support/net_ssh_story_helpers.rb

@@ -0,0 +1,17 @@
+module NetSSHStoryHelpers
+  require 'net/ssh/test'
+  include Net::SSH::Test
+
+  def story_with_new_channel
+    story do |session|
+      ch = session.opens_channel
+      yield ch
+      ch.gets_close
+      ch.sends_close
+    end
+  end
+
+  def story_completed?
+    socket.script.events.empty?
+  end
+end