Add support for Pg/Cockroach user defined enumerated types

[mcadecio]

I would like to use my user-defined enum type. The enum types is as follows:

CREATE TYPE bug_status AS ENUM ('new', 'open', 'closed');

CREATE TABLE bug (
    id serial,
    description text,
    status bug_status
);

Current error:
ERROR|0521-10:00:22 897|vert.x-eventloop-thread-3|RestApiVerticle|Failed to create router:
java.lang.IllegalArgumentException: No enum constant com.dercio.database_proxy.postgres.type.PgType.USER-DEFINED