Oracle create table with default value is not working

Following create table statement is not recognized by the parser, which is valid statement for Oracle database. 

```
from simple_ddl_parser import DDLParser
DDLParser("create table test ( col varchar2(30 char) default user not null);").run()
```
result is empty list.

python version 3.9.5
simple-ddl-parser==0.29.0
