Detector Fix: Postgres

[ankushgoel27]

https://github.com/trufflesecurity/trufflehog/blob/3ee9c2f1af6365e0db6dc036826196bae21d34e7/pkg/detectors/postgres/postgres.go#L51

Postgres detector not account for drivers and other formats and the regex is also very weak.

SQLALCHEMY_DB_URL = "postgresql+psycopg2://postgres:6gpT;4UR[]dZ7?$9@35.206.9.236/postgres" not being picked up by trufflehog