Revert "Merge pull request #185 from zendesk/gabetax/explicit_namespace_class"

This reverts commit d13f2a395d58ccb0c6b57d7845dee5d9f80706c4, reversing
changes made to c4cf7ff23d7f30eac1220edb978c86b1bfcb983a.
lets lock hashie to < 4, just in case major version bumps do break the client