chore(release): Bump version to v0.3.0
chore(release): Bump version to v0.3.0+git
fix(event): Chase etcd index on EcodeEventIndexCleared
refactor(registry): Use a single watcher in EventStream
refactor(registry): Check for path prefix in event filters
Merge pull request #411 from bcwaldon/chase-that-index

Chase that index
fix(registry): lazily migrate legacy payloads
Merge pull request #413 from bcwaldon/lazy-migrate

fix(registry): lazily migrate legacy payloads
refactor(registry): move fleetctl's Registry interface to registry proper
Merge pull request #323 from jonboulle/323

refactor(registry): improve registry interface and obviate fleetctl's special one
fix(systemd): Use LinkUnitFiles rather than EnableUnitFiles
Merge pull request #414 from bcwaldon/quit-enabling

fix(systemd): Use LinkUnitFiles rather than EnableUnitFiles
fix(agent): Log error on GetUnitState failure
fix(systemd): Bubble up error from LoadJob
Merge pull request #416 from bcwaldon/report-systemd-load-err

Report systemd load err
fix(ssh): format host entries in known_hosts correctly

This change also adds sshDefaultPort in the ssh module only if necessary
rather than tacking it on arbitrarily in fleetctl.
refactor(ssh): improve known hosts handling to better match spec
refactor(job): Drop unused Job.Type method
refactor(unit): rework supported unit type-handling
chore(ssh): add LICENSE information