Support multi functionality in server.js
I wouldn't pass file folders/files to a fn like that, I'd rather pass the functionality subject like:

myModule.addNewFunctionlity('geoMapping');
myModule.addNewFunctionlity('cookieService');


then refactor you fn nomenclature, maybe 

myModule.addNewFunctionlity('geo.geoMapping');
myModule.addNewFunctionlity('frontend.cookieService');


If you think you really need to setup file/folder structure, then apply maybe a setupPath() fn:

myModule.setupPath({ folderPath:__dirname + '/files2'} );


so that in 5-7 years you and others will understand at a glance what 
addNewFunctionlity() and setupPath() is about :)