Log Message:
Update ruby-raindrops to 0.17.0.

=== raindrops 0.17.0 - rack 2.x updates / 2016-07-31 15:19 UTC

  This release features minor updates to support rack 2.x
  while maintaining support for rack 1.2 and later.
  As a result, Ruby 1.8.6 compatibility is gone, but
  Ruby 1.8.7 probably still works, for now.

  There's also a minor warning fix, doc updates, and
  the homepage now supports HTTPS (HTTP remains supported)

  5 changes since raindrops 0.16.0:
        drop Rack::Utils.bytesize dependency
        gemspec: bump Rack dependency
        linux_inet_diag: GCC attribute format check
        use HTTPS and move homepage to https://bogomips.org/raindrops/
        examples: add yahns config, zbatery is abandoned