Added missing `empty` tests for evaluating environment
Added missing `empty` tests for evaluating environment

kvalle/diy-lang,rcanepa/diy-lisp,rcanepa/diy-lisp,beni55/diy-lisp,beni55/diy-lisp,codecop/diy-lang,couchemar/diy-lisp,couchemar/diy-lisp,joelchelliah/diy-lisp,kvalle/diy-lisp,kvalle/diy-lang,codecop/diy-lang,joelchelliah/diy-lisp,kvalle/diy-lisp