Iredis

- Feature: Support `PEEK` Command.

- Refactor: split completer update and response render; Move cli tests to travis
ci. (Thanks: [ruohan.chen])
- Support stream commands. _ Timestamp completer support. _ Stream command
renders and lexers.
- Bugfix: When response is None,
`iredis.completers.udpate_completer_for_responase` will raise Exception.

- Bugfix: Multi spaces between commands can be recognised as correct commands
now.
- Feature: Warning on dangerous command.

- Bugfix: Fix HELP command can not render markdown with a `<h3>` header.
- Bugfix: Pipeline using a builtin Python API.

- Bugfix: previous version of iredis didn't package redis-doc correctly.
- Feature: prompt for dangerous commands.

- Support config files.