Update install.md: Python 2.6 is supported again

docs/install.md

@@ -2,12 +2,11 @@
 
 ### REQUIREMENTS
 
-- Python v2.7, 3.0, or 2.6 with argparse
-- Bash v4.0 for tab completion
+- Python v2.6
+- Bash v4.0 for tab completion (or zsh)
 
 If you are unable to update Python to a supported version, older versions of autojump can be [downloaded][dl] and installed manually.
 
-- Python v2.6 is supported by [release v19][v19].
 - Python v2.4 is supported by [release v12][v12].
 
 ### AUTOMATIC INSTALLATION
@@ -71,5 +70,4 @@ If you keep getting `autojump: command not found` at the prompt, do:`unset PROMP
 
 [dl]: https://github.com/joelthelion/autojump/downloads
 [v12]: https://github.com/downloads/joelthelion/autojump/autojump_v12.tar.gz
-[v19]: https://github.com/downloads/joelthelion/autojump/autojump_v19.tar.gz
 [wiki]: https://github.com/joelthelion/autojump/wiki