Rise network-transport dependency.

As it was noted by Magnus Morton, we need to rise lower
network-transport dependency, because we rely on existance
of Binary instance for internal datatypes, that were
introduced only in network-transport >= 0.4.
fix travis file
Port benchmarks to new API
Merge branch 'fix-benchmarks' into loosen-deps
Fix travis file
Merge branch 'loosen-deps' into zmq-exceptions
Fix compilation warnings.