use villein v0.3.0
Add inspection methods

- Fetcher#queue_size
- Agent#existing_packages
- Agent#status
oops, it's not `fetching`
docs
Respond to `mamiya:status` query events

- dummy_serf: mock around querying
Mamiya::Master: minimal impl of master status
[oops] Fix typo
add todo
[oops] fix typo (2)
Unlink file on exception because may be broken
Show pending jobs on fetching events