Print all matches instead of erring

[sanxiyn]

This implements a wishlist item from #77, cc @najamelan.

Before:

error: There are multiple `regex` packages in your project, and the specification `regex` is ambiguous.
Please re-run this command with `-p <spec>` where `<spec>` is one of the following:
  regex:0.2.2
  regex:1.0.2

After:

regex v0.2.2
├── env_logger v0.5.6
│   └── pretty_env_logger v0.2.2
│       └── linky v0.1.6 (/home/sanxiyn/github/linky)
└── linky v0.1.6 (/home/sanxiyn/github/linky) (*)

regex v1.0.2
└── publicsuffix v1.5.2
    └── cookie_store v0.7.0
        └── reqwest v0.9.17
            └── linky v0.1.6 (/home/sanxiyn/github/linky)

[sanxiyn]

Ping?

[sanxiyn]

I re-implemented this on top of cargo-metadata rewrite on master branch.

Please review! Thanks.