FIxing a problem caused by the strange "command command -v rbenv" command

Some systems don't have a ```command``` command ; testing for it before trying to execute it is better form.

fix(scorphish): redirect Git stderr to /dev/null while

Fix #454. Thanks @bucaran 👍Signed-off-by: Pablo Santiago Blum de Aguiar <scorphus@gmail.com>

Custom completions load fix

Improve scorphish theme

add commits ahead indicator to scorphish

Modify README.md

Typo fixed.

themes: add a new theme, scorphish

Add installation note about config.fish

Add a note to make it clearer what happens to existing config.fish files when installing omf.

Some improvements on robbyrussel theme

[bobthefish] allow git untracked files override

Showing untracked files can be (very) slow on large NFS mounts. Allow the user to disable the '...' output when there are untracked files, either globally via fish config:

    set -g theme_display_git_untracked no

 or locally via git repo config:

    git config bash.showUntrackedFiles false

Fixes #434

Fix extraneous output from `type` on some fishes.

gnuykeaj theme

Added godfather theme.

adds the trout theme