Support Create Table Like Statement

[reata]

drop table  if exists tab_a;
create table if not exists tab_a like tab_b;

drop before create, the result is tab_a exists after the above statements;

If we switch the order:

create table if not exists tab_a like tab_b;
drop table  if exists tab_a;

Although the above statements make no sense, still, we should output result as tab_a does not exist.

Under current circumstances, both cases will be that tab_a does not exists since tab_a is identified as temp table. This is related to #23

[reata]

The Drop Table order issue is already taken care of with #22 . And the new problem is that create like Statement is not supported. An AssertError is raised because like is identified as Comparison Operator.

CREATE TABLE new_tbl LIKE orig_tbl;