build: Separate target for minion container build
build: Separate target for minion container build

This is useful for developers working on the minion.

kklin/quilt,kklin/kelda,kelda/kelda,kayousterhout/quilt,stevenlin598/quilt,PenguinToast/quilt,stevenlin598/quilt,kklin/kelda,ZhongtianWang/quilt,tejasmanohar/quilt,ZhongtianWang/quilt,kayousterhout/quilt,mmussomele/quilt,LuiseV/quilt,kelda/kelda,kklin/quilt,secant/quilt,NetSys/quilt,secant/quilt,kelda/kelda,kklin/quilt,mmussomele/quilt,LuiseV/quilt,ejj/quilt-dev,ZhongtianWang/quilt,akshayknarayan/quilt,akshayknarayan/quilt,PenguinToast/quilt,secant/quilt,tejasmanohar/quilt,PenguinToast/quilt,mmussomele/quilt,LuiseV/quilt,LuiseV/quilt,quilt/quilt,NetSys/quilt,LuiseV/quilt,ZhongtianWang/quilt,secant/quilt,quilt/quilt,ejj/quilt-dev,NetSys/quilt,NetSys/quilt,kelda/kelda,stevenlin598/quilt,mmussomele/quilt,kklin/quilt,secant/quilt,quilt/quilt,kayousterhout/quilt,NetSys/quilt,ejj/quilt-dev,mmussomele/quilt,PenguinToast/quilt,stevenlin598/quilt,quilt/quilt,kayousterhout/quilt,akshayknarayan/quilt,ejj/quilt-dev,kklin/kelda,kklin/kelda,stevenlin598/quilt,PenguinToast/quilt,stevenlin598/quilt,tejasmanohar/quilt,mmussomele/quilt,tejasmanohar/quilt,akshayknarayan/quilt