bpmn js download url: git clone https://github.com/bpmn-io/bpmn-js.git -b v13.2.1 .

We made some changes for easyflow. Details are as follows:
1.For the purpose of using Viewer and Modeler at the same time, we change rollup.config.js to export different control name.(see rollup.config.js)
2.For the purpose of supporting other language of 'ID', we change node_modules\moddle-xml\dist\index.js and node_modules\moddle-xml\dist\index.esm.js, commenting the line `throw new Error('illegal ID <' + id + '>');`. 
After above change ,we can run 'npm run distro' command to build a new version of bpmn.js.