Http-prompt

* Add HTTP `CONNECT` method (144)
* Add `clear` command (126)
* Fix bug: root path `/` leads to crash (145)
* Fix bug: Cookie related `AttributeError` on Python 2 (145)

* Fix bug: Handle OpenAPI `basePath` properly (140, 141)

* Fix bug: Allow passing a URL to `--spec` (136)
* Upgrade and pin prompt_toolkit at 1.x (138)

* Add `--env` CLI option to preload environment (131, 132)
* Add support for persistent history (130)
* Drop Python 2.6 support (129)
* Ignore `data.json` generated from tests (128)

* Fix typos in documentation (119, 121)
* Use tuples inside of str.startswith (122)
* Remove extra argument from six.u (123)
* Conditionally install ordereddict package on Python 2.6 (124)

* cd without an argument resets URL to root (114)
* Fix --spec crash issue on Windows (116)