reduced fidelity regarding peer dependencies

[eladb]

PR #306 reduced the fidelity of the version information since there was no way to distinguish between the version required as a normal dependency and the version required as a peer, and there is no way to indicate that a dependency is only required as a peer.

[rix0rrr]

In what case does it fail?

[eladb]

Updated the title: this is just about loss of fidelity. The failure was actually legitimate since the peer didn't semver-match the normal dependency.