sanposhiho: Support custom plugins in the simulator

JobBuild
177
05-21 09:06
pull-kube-scheduler-simulator-backend-lint 1530857190175281152 1530768486513512448 1527951211959947264 1527949236866387968 1527945536206802944 1527938361698816000
pull-kube-scheduler-simulator-backend-unit-test 1530857190238195712 1530768486601592832 1527951212014473216 1527949236925108224 1527945536278106112 1527938361770119168
pull-kube-scheduler-simulator-frontend-lint 1530857190208835584 1530768486559649792 1527951211985113088 1527949236891553792 1527945536240357376 1527938361740759040