Remove pyenv and add new shell theme

I enjoyed bobthefish quite a bit, but the nerd fonts on the CLI were
screwing up Emacs, and that's a non-starter for me.

One thing I like about cmorrell is that it has the host in the terminal
line, so I can tell which machine I'm on.

config/fish/fishfile

@@ -2,7 +2,6 @@ jethrokuan/z
 jethrokuan/fzf
 simnalamburt/shellder
 fishgretel/fasd
-oh-my-fish/theme-bobthefish
-yyuu/pyenv
 2m/fish-gpg-tty
 asdf-vm/asdf
+oh-my-fish/theme-cmorrell.com