bump(coreos/go-systemd): f743bc15d6bddd23662280b4ad20f7c874cdd5ad
Merge pull request #391 from bcwaldon/bump-go-systemd

Upgrade coreos/go-systemd
chore(engine): fix badly formatted log message
Merge pull request #392 from jonboulle/pedantry!

chore(engine): fix badly formatted log message
refactor(registry, tests): make keyPrefix configurable

Previously all registry access was hardcoded to a specific prefix
(/_coreos.com/fleet). This makes the endpoint configurable through both
fleet and the client. Accordingly, the functional tests are updated to
take advantage of this, which means they should no longer conflict with
any instances of fleet which happen to be running in the environment
used for functional testing.
s/KeyPrefix/EtcdKeyPrefix/ + rebase
refactor(*): move default key prefix to registry
tests(fleetctl): add tests for parseEndpoint