Bump github.com/libp2p/go-libp2p in /tests_interop/go_pkgs/examples

Bumps [github.com/libp2p/go-libp2p](https://github.com/libp2p/go-libp2p) from 0.18.0 to 0.27.8.
- [Release notes](https://github.com/libp2p/go-libp2p/releases)
- [Changelog](https://github.com/libp2p/go-libp2p/blob/master/CHANGELOG.md)
- [Commits](https://github.com/libp2p/go-libp2p/compare/v0.18.0...v0.27.8)

---
updated-dependencies:
- dependency-name: github.com/libp2p/go-libp2p
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

tests_interop/go_pkgs/examples/go.mod

@@ -4,9 +4,9 @@ go 1.12
 
 require (
 	github.com/ipfs/go-log v1.0.5
-	github.com/libp2p/go-libp2p v0.18.0
-	github.com/libp2p/go-libp2p-core v0.14.0
+	github.com/libp2p/go-libp2p v0.27.8
+	github.com/libp2p/go-libp2p-core v0.19.0
 	github.com/libp2p/go-libp2p-noise v0.3.0
 	github.com/libp2p/go-libp2p-secio v0.2.2
-	github.com/multiformats/go-multiaddr v0.5.0
+	github.com/multiformats/go-multiaddr v0.9.0
 )