Merge pull request #59 from voxik/net-ssh-4-compat

Fix compatiblity with net-ssh 4.0+

Author: mfazekas

test/test_download.rb

@@ -139,7 +139,9 @@ def test_download_file_should_transfer_remote_to_local_buffer
 
   def test_download_directory_to_buffer_should_fail
     expect_sftp_session :server_version => 3
-    assert_raises(ArgumentError) { sftp.download("/path/to/remote", StringIO.new, :recursive => true) }
+    Net::SSH::Test::Extensions::IO.with_test_extension do
+      assert_raises(ArgumentError) { sftp.download("/path/to/remote", StringIO.new, :recursive => true) }
+    end
   end
 
   private

test/test_session.rb

@@ -660,8 +660,10 @@ def test_unblock_bang_should_block_and_return_response
 
     def assert_not_implemented(server_version, command, *args)
       expect_sftp_session :server_version => 1
-      sftp.connect!
-      assert_raises(NotImplementedError) { sftp.send(command, *args) }
+      Net::SSH::Test::Extensions::IO.with_test_extension do
+        sftp.connect!
+        assert_raises(NotImplementedError) { sftp.send(command, *args) }
+      end
     end
 
     def assert_command_with_callback(command, *args)