Incorrect SBGN file format following writing the render information

[ibalaur]

Hello,

I am not sure whether this is related to issue #51, but I get an "invalid file format" after writing the render information. The error refers to <<Attribute "xmlns" was already specified for element "renderInformation".>> Please see the attached simple test case on this. If this is already addressed, could you please create a new jar? Thank you very much.

WriteRenderExtensionExample.java.zip

test-output.sbgn.zip