Revert "try to purge docker cache manually"
Revert "try to purge docker cache manually"

This reverts commit de743413174729cd574ba92fa0e5f348c0febb30.

openzipkin/zipkin,openzipkin/zipkin,openzipkin/zipkin,twitter/zipkin,openzipkin/zipkin,twitter/zipkin,twitter/zipkin,openzipkin/zipkin,twitter/zipkin