Java project, include frontend library(Polymer)

I try to work on apache2 licensed project on github, it is a j2ee webap, as user UI I want to use Polymer libraries... Now I don't know to include all needed js/html files in depository or to leave only bowler file ?

• If i will include all files it will be easy to start project but entire repository will grow and probably will be required to update files when new version of frontend will be available and so on...

• If I will leave only bower file, someone who cloned project will be required to do more workarounds to start project

Someone had similar issues ? how was solved they ?