Upgrade libp2p to enable yamux gains

[pawanjay176]

Issue Addressed

N/A

Proposed Changes

Upgrade to a libp2p sigp branch which contains the yamux improvements. The libp2p branch is essentially the commit being used in @jxs 's PR merged with libp2p master.
Also upgrades to a discv5 branch that uses the updated libp2p commit.

Libp2p branch: https://github.com/sigp/rust-libp2p/tree/lighthouse-gossipsub-yamux
Discv5 branch: https://github.com/sigp/discv5/tree/lighthouse-with-yamux

Related sigp#4996

[jxs]

Suggested change

	discv5 = { git="https://github.com/sigp/discv5", rev="1b5218d01015023f32e12c0a9ac6780759a550bf", features = ["libp2p"] }
	discv5 = { version = "0.4.0", features = ["libp2p"] }

age released a new version Pawan

[pawanjay176]

Discv5 has the libp2p feature for using PeerIds, so we need to update the libp2p version in discv5's Cargo.toml as well
We were using the lighthouse branch.
I upgraded it to use the branch I made (https://github.com/sigp/discv5/tree/lighthouse-with-yamux), this branch builds upon version 0.4.0

[jxs]

can we depend on the branch instead for better clarity Pawan? The Cargo.lock file will still have the revision

[pawanjay176]

I'm a little unsure about how branch works cached dependencies vs fresh install. This is my ignorance, so I'll do some reading on how dependency management works with cargo.
For now, I'll just add a comment specifying the branch used with the rev since we want to deploy this to our nodes asap.