Allow creating PostgreSQL database "with owner"

[AnthonyMastrean]

The PostgreSQL CREATE DATABASE statement requires a superuser account and the WITH OWNER clause allows you to change ownership to, say, a normal service account.

It would be super nice to have this option in the PostgresqlDatabase method to minimize the use of a superuser connection string.

            sqlCommandText = string.Format
                (
                    "create database \"{0}\";",
                    databaseName
                );

https://github.com/DbUp/DbUp/blob/master/src/dbup-postgresql/PostgresqlExtensions.cs#L189-L193

[AaronShiels]

Would be great to see this.

We've implemented a workaround to a similar problem (assigning ownership at the schema level) by inheriting the ScriptExecutor and override the GetVerifySchemaSql(string schema);, so this is definitely on my wishlist.

[aashikgowda]

Created #37 to address this issue.