http_spew 0.7.0 - modernizing for newer Rubies
Ruby 2.3+ is now required as kgio dependencies are gone.
This is unlikely to be a problem in practice, as hardly
anybody uses this at the moment.
5 changes since 0.6.0:
remove most uses of kgio
make kgio entirely optional
update to only use public email address
http_spew: remove kgio require at top level
gemspec: remove olddoc as a build dependency