Github user jongyoul commented on the issue:
https://github.com/apache/zeppelin/pull/3100
What I thought is to move all interpreters modules to optional. For
instance, running `mvn package` will create only zeppelin-* modules, and if
users want to build spark, users should do add `-P spark` as an option like
`mvn package -Pspark`. What do you think of it? The main reason why I'd like to
do it is to make Zeppelin's code more friendly for IDE. WDYT?---
