Remove internet traffic assertion from missing dependency test.
Remove internet traffic assertion from missing dependency test.

* Machete 0.0.30 breaks this assertion, and it can be removed without
  sacrificing code coverage.

Signed-off-by: Brandon Shroyer <d370be3f39cb88690ed16d1a7b77debc20949e86@pivotal.io>

cloudfoundry/go-buildpack,cloudfoundry/go-buildpack,cloudfoundry/go-buildpack