see sporkmonger/addressable#77. Support for nested query parameters has been removed in 2.2.9, 2.2.8 is working just fine.
HI, can you please change add_runtime_dependency in gemspec, to require adressable 2.2.8.
After merging this pull request I get local build failures, but travis seems to indicate everything is fine. So use with caution. I'll still close this issue for now and will investigate.