upgrade tmp (no code changes necessary)

[FauxFaux]

tmp 0.1 requires node 0.10, we already require node 4.

We only use tmpNameSync, which hasn't had any changes, except maybe the addition of a tries parameter, which we do not expose, and probably don't need to.

Older versions are deprecated, so give me warnings when I end up installing them.

[antonk52]

I cannot see why travis build is failing but this PR has good intentions. tmp should be updated as it has deprecated dependencies which already has been removed in favor of node's native modules. Any help with travis? @mrkmg