Remove useless dep features

[PrivateRookie]

I use nom & nom-tracable in my project, when profiling build time I found that, nom-tracable costs about 8s to build, after removing "fold", "parsing" & "extra-traits" in dep, build time reduce to 7s(my cpu is i7-8559U), which is quite a improvement, I think it make sense to remove those features to faster compile.