Fix for Python3

In Python3 without universal_newlines set to True
output from Popen was byte-encoded.
Fix `docker rmi` tab completion

This is exactly what happens on tab completion for docker rmi. This commit
fixes that.

```sh
$ docker rmi <hit TAB>
_arguments:comparguments:312: invalid argument: __docker_images
_arguments:comparguments:312: invalid argument: __docker_images
_arguments:comparguments:312: invalid argument: __docker_images
```
Merge pull request #2693 from javiertejero/master

Fix `docker rmi` tab completion
Merge pull request #2729 from grodzik/master

Fix for Python3
Add 'chris' theme
Update zsh prompt
Add custom dir to repo
Remove Climate aliases
Remove spec alias
Add irc alias for weechat-curses
Remove before and after context on grep alias
Add gap alias, remove grep alias
Add custom scripts to repository
Rename scripts to have correct load order
Remove unnecessary init scripts
Change LSCOLORS to better match Thayer color scheme
Move path stuff to oh-my-zsh config
Add node binaries to path
Remove custom LS colors for zsh
Remove custom Square stuff