GitLab

Bumps [github.com/libp2p/go-libp2p-core](https://github.com/libp2p/go-libp2p-core) from 0.2.5 to 0.3.0.
- [Release notes](https://github.com/libp2p/go-libp2p-core/releases)
- [Commits](https://github.com/libp2p/go-libp2p-core/compare/v0.2.5...v0.3.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [github.com/libp2p/go-libp2p-core](https://github.com/libp2p/go-libp2p-core) from 0.0.1 to 0.2.5.
- [Release notes](https://github.com/libp2p/go-libp2p-core/releases)
- [Commits](https://github.com/libp2p/go-libp2p-core/compare/v0.0.1...v0.2.5)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

It's unmaintained and pulls in github.com/whyrusleeping/cbor. This patch
explicitly re-implements the minimally needed features.

Also fixes #12.