Properly handle remote packages cache
Properly handle remote packages cache

Normal npm packages when requested have information about all versions.
Since we don't support remote packages (e.g. file-system or git-based),
this premise is not true, and we can run into problems (e.g.
https://github.com/anvaka/npmgraph.an/issues/12)

This change takes into account remote/not-remote nature of a package,
and treates thesm accordingly in the cache

anvaka/npmgraphbuilder