circleci: move yarn to apt-get
circleci: move yarn to apt-get

- Continue to use yarn instead of npm through ci pipeline to cache
things more

yldio/joyent-portal,geek/joyent-portal,yldio/copilot,yldio/copilot,yldio/copilot,geek/joyent-portal,yldio/joyent-portal