GitLab

Bumps [github.com/libp2p/go-libp2p-blankhost](https://github.com/libp2p/go-libp2p-blankhost) from 0.1.4 to 0.1.6.
- [Release notes](https://github.com/libp2p/go-libp2p-blankhost/releases)
- [Commits](https://github.com/libp2p/go-libp2p-blankhost/compare/v0.1.4...v0.1.6)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [github.com/libp2p/go-libp2p-core](https://github.com/libp2p/go-libp2p-core) from 0.5.3 to 0.5.6.
- [Release notes](https://github.com/libp2p/go-libp2p-core/releases)
- [Commits](https://github.com/libp2p/go-libp2p-core/compare/v0.5.3...v0.5.6)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [github.com/libp2p/go-libp2p-swarm](https://github.com/libp2p/go-libp2p-swarm) from 0.2.3 to 0.2.4.
- [Release notes](https://github.com/libp2p/go-libp2p-swarm/releases)
- [Commits](https://github.com/libp2p/go-libp2p-swarm/compare/v0.2.3...v0.2.4)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

travis managed to take more than 3 seconds for one or two heartbeat sleeps; give it 10 seconds.

apparently creating the score object and calling refreshScores can take 500ms on travis!

- Specify backoff in PRUNE message
- Obey peer backoff if specified
- Remove BackoffPenalty, handle lack of respect for backoff through P7