travis: Add help2man
travis: Add help2man

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

lxc/cgmanager,udeved/cgmanager,hallyn/cgmanager,hustcat/cgmanager,hallyn/cgmanager,lxc/cgmanager,hallyn/cgmanager-pkg-ubuntu,hallyn/cgmanager-pkg-ubuntu,hustcat/cgmanager,udeved/cgmanager