Fix go test

If no GO is available, there should be no output.

powerlevel9k.zsh-theme

@@ -471,7 +471,7 @@ prompt_dir() {
 # GO prompt
 prompt_go_version() {
   local go_version
-  go_version=$(go version 2>&1 | sed -E "s/.*(go[0-9.]*).*/\1/")
+  go_version=$(go version 2>/dev/null | sed -E "s/.*(go[0-9.]*).*/\1/")
 
   if [[ -n "$go_version" ]]; then
     "$1_prompt_segment" "$0" "$2" "green" "255" "$go_version"