fix(python): complete micropython and pyston script args consistently

...with python and pypy variants.

completions/python

@@ -63,7 +63,7 @@ _comp_cmd_python()
             _comp_compgen -- -W "help off"
             return
             ;;
-        !(?(*/)python*([0-9.])|?(*/)pypy*([0-9.])|-?))
+        !(?(*/)?(micro)python*([0-9.])|?(*/)py@(py|ston)*([0-9.])|-?))
             if [[ $cword -lt 2 || ${words[cword - 2]} != -[QWX] ]]; then
                 _comp_compgen_filedir
                 return