Revert "infra: fix for travis:osx problem with 'shell_session_update: command not found'"
Revert "infra: fix for travis:osx problem with 'shell_session_update: command not found'"

This reverts commit 5b36d9e7c7973f5447e887b23ebab5e4a8967e6a.

rnveach/checkstyle,rnveach/checkstyle,checkstyle/checkstyle,romani/checkstyle,checkstyle/checkstyle,romani/checkstyle,jonmbake/checkstyle,checkstyle/checkstyle,romani/checkstyle,checkstyle/checkstyle,romani/checkstyle,romani/checkstyle,rnveach/checkstyle,jonmbake/checkstyle,rnveach/checkstyle,jonmbake/checkstyle,checkstyle/checkstyle,romani/checkstyle,checkstyle/checkstyle,rnveach/checkstyle,rnveach/checkstyle