VerifyCa represents Always TLS (verify that the certificate presented by the server was signed by a trusted CA).

VerifyFull represents Always TLS (verify that the certification presented by the server was signed by a trusted CA and the server host name matches the one in the certificate).

VerifyNone represents Always TLS (skip verification).

PostgresStoreConfig defines Postgres store configuration.

TLSMode modes available here https://godoc.org/github.com/lib/pq.