Plugin changed to work with gulp 3.4.0 (stream handling needs to be implemented)

Thank you for your great plugin. I throws an error with gulp 3.4.0 - so I changed the code. You may merge the changes if you are interested.

The plugin does not work with gulp 3.4.0. I changed the plugin to handle buffers and commented out the line "file = _.clone(file);" because it created an error and seams not to be needed.

Signed-off-by: uhunkler <urs.hunkler@unodo.de>