Add secgroup cleanup and restrict sudo privileges

Adjust for limited sudo privileges for the jenkins user

Add post-destroy info dump

Remove shim for hashsum mismatch issue in Juju 1.25.6

Bail earlier if mojo operations fail

Update jenkins sudoers

Fixes and workarounds for:
 - https://bugs.launchpad.net/charm-test-infra/+bug/1647000
 - https://github.com/juju/charmstore-client/issues/104
 - https://github.com/juju/docs/issues/1555
 - https://bugs.launchpad.net/bugs/1541482
 - https://bugs.launchpad.net/bugs/1647000
 - https://bugs.launchpad.net/bugs/1646909
 - https://bugs.launchpad.net/bugs/1333162
 - https://bugs.launchpad.net/bugs/1625624
 - https://bugs.launchpad.net/bugs/1570216