Title: M1: Basic artifact storage

### Blobs

- [X] Proto definition for archive blobs
- [X] Database schema for archive blobs
- [X] SQL migration (using [sql-migrate](https://github.com/rubenv/sql-migrate))
- [X] Go package for archive blobs
- [X] blob store
- [X] syncq
- [X] CLI tool for inserting blobs

### Artifacts
- [X] What does an artifact look like? Develop the data model.
- [ ] Proto definitions for an archive entry
- [ ] Database schema for archive entries
- [ ] SQL migration

### Web service
- [ ] gRPC service
- [ ] HTTP backend that talks to the gRPC service
- [ ] HTML frontend with authentication
- [ ] (Bonus) CLI tool to interact with the webserver