Version autocomplete `use` command

completions/rbenv.bash

@@ -17,7 +17,7 @@ _rbenv() {
   local prev="${COMP_WORDS[COMP_CWORD-1]}"
 
   case "$prev" in
-  set-* | global | local | prefix )
+  set-* | global | local | prefix | use )
     _rbenv_versions
     ;;
   * )

completions/rbenv.zsh

@@ -14,7 +14,7 @@ _rbenv_versions() {
 
 _rbenv() {
   case "$words[2]" in
-    set-* | global | local | prefix ) _rbenv_versions ;;
+    set-* | global | local | prefix | use ) _rbenv_versions ;;
     * ) _rbenv_commands ;;
   esac
 }