HTTPie 0.9.0 发布支持客户端 SSL 证书

HTTPie 0.9.0 发布了，HTTPie 是一个开源的命令行的 HTTP 工具包，提供命令行交互方式来访问 HTTP 服务。

该版本改进内容包括：

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 suppor.
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.