raindrops 0.13.0 several minor fixes and improvements

Most notably, this release is necessary for Ruby 2.2 (dev).
Thanks to Koichi Sasada for the bug report!

Eric Wong (5):
      Rakefile: remove raa_update task
      last_data_recv: do not assume Unicorn includes all constants
      raindrops.gemspec: add wrongdoc dev dependency
      linux_inet_diag: fix Ruby 2.2 (dev) build
      license: use LGPLv2.1 or later (was LGPL (2.1|3.0)-only)

Hleb Valoshka (1):
      Remove Scope IDs from IPv6 addresses.