refactor(agent): Drop single-use method newFakeMachine
refactor(agent): Move fakeMachine to machine pkg
Merge pull request #488 from bcwaldon/fakemachine

Relocate fakeMachine
refactor(registry): Move TestRegistry to registry pkg
refactor(TestRegistry): embed Registry iface and drop unimplemented methods
refactor(FakeRegistry): Use pointer receivers
refactor(registry): s/TestRegistry/FakeRegistry/
refactor(FakeRegistry): Use map to store Jobs
test(FakeRegistry): Add testing of create/list/destroy jobs
refactor(FakeRegistry): Use methods to load fixtures
feat(FakeRegistry): Implement JobBid-related methods
feat(FakeRegistry): implement SaveUnitState
feat(FakeRegistry): implement Set/GetJobTargetState
fix(FakeRegistry): Protect access with mutex