Updated to httpie 0.9.1

0.9.1 (2015-02-07)
  * Added support for Requests transport adapter plugins to enable plugin-provided features such as unix socket communication and HTTP/2.

0.9.0 (2015-01-31)
  * Added --cert and --cert-key parameters to specify a client side certificate and private key for SSL
  * Improved unicode support.
  * Improved terminal color depth detection via curses.
  * To make it easier to deal with Windows paths in request items, \ now only escapes special characters (the ones that are used as key-value separators by HTTPie).
  * Switched from unittest to pytest.
  * Added Python wheel support.
  * Various test suite improvements.
  * Added CONTRIBUTING.
  * Fixed User-Agent overwriting when used within a session.
  * Fixed handling of empty passwords in URL credentials.
  * Fixed multiple file uploads with the same form field name.
  * Fixed --output=/dev/null on Linux.
  * Miscellaneous bugfixes.

(imil)