Log Message:
Update ruby-kgio to 2.11.0.

=== kgio 2.11.0 - reverting 2.10.0 breakage / 2016-12-16 22:56 UTC

  Mainly this release reverts back to kgio 2.9.3 behavior by
  supporting "autopush" functionality in the C extension.
  Removing this feature in 2.10.0 was a monumental mistake(*) on
  my part which caused a performance regression for ONE known user
  of kgio on the deprecated (but supported) Rainbows! server.

  This release does not affect known users outside of Rainbows!,
  but we may have unknown users, too.

  The attempt at a pure Ruby version of autopush had flaws and
  regressions in real-world testing, so that was abandoned.

  So yeah, kgio will be supported indefinitely even in the face
  of internal changes to MRI, but I strongly discourage its use
  for new projects.
  Users who only support Ruby 2.3 (and later) are encouraged to
  use `exception: false` with all *_nonblock methods.

  4 changes since 2.10.0:

        resurrect Kgio.autopush support in pure Ruby [REVERTED]
        reinstate the original (and dangerous) autopush in C
        TODO: update with Ruby 2.3 status
        test: increase test data sizes to fill socket buffers

  (*) - as was making this a separate project, at all