Log Message:
Update ruby-http to 2.2.0.

Upstream changes (from CHANGES.md):

## 2.2.0 (2017-02-03)

* [#375](https://github.com/httprb/http/pull/375)
  Add support for automatic Gzip/Inflate
  ([@Bonias])

* [#390](https://github.com/httprb/http/pull/390)
  Add REPORT to the list of valid HTTP verbs
  ([@ixti])

## 2.1.0 (2016-11-08)

* [#370](https://github.com/httprb/http/issues/370)
  Add Headers#include?
  ([@ixti])

* [#364](https://github.com/httprb/http/issues/364)
  Add HTTP::Response#connection
  ([@janko-m])

* [#362](https://github.com/httprb/http/issues/362)
  connect_ssl uses connect_timeout (Closes #359)
  ([@TiagoCardoso1983])