The library semantic-version changed a lot during the last versions,
making the Metadata class very fragile.
A custom-made semantic version parsed, based on some Cargo specifics,
has been implemented to replace the old parser.
As a result of that, new features were implemented, like the support for
wildcard expressions, as documented in the Cargo book.
Fix: #93
We don't need it right now since we don't support filtering unneeded
dependencies on cargo level.
Signed-off-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org>