Commit 5c13765168 removed postgre registration triggerd
by the automatic gofmt command but it was the only where pg is registered. This commit
fixes behavior and adds unit tests to check whether postgre & sql are registered or not.
* The user is required to specify a table name and database connection
information in the configuration file.
* INSERTs and DELETEs are done via prepared statements for speed.
* Assumes a table structure, and requires PostgreSQL 9.5 or above due to
the use of UPSERT.
* Creates the table if it does not exist with the given table name using
a query like:
CREATE TABLE myminio (
key varchar PRIMARY KEY,
value JSONB
);
* Vendors some required libraries.