Fix use of CARETCOLOR in avit theme

$CARETCOLOR was not to actually colour the caret, so change to root user
wouldn't show in the prompt. Now both ▶ and ◀ follow $CARETCOLOR.

themes/avit.zsh-theme

 # AVIT ZSH Theme
 
 PROMPT='
-$(_user_host)$(_current_dir) $(git_prompt_info) $(_ruby_version)
+$(_user_host)${_current_dir} $(git_prompt_info) $(_ruby_version)
 %{$fg[$CARETCOLOR]%}▶%{$resetcolor%} '
 
 PROMPT2='%{$fg[$CARETCOLOR]%}◀%{$reset_color%} '