v3.18.1

• Added conn.Ping(ctx) method for check availability of conn.Conn
• Refactored cluster.Cluster.Get(ctx) to return only available connection (instead of returning any connection from balancer)
• Added address to error description thrown from conn.take()
• Renamed package internal/db to internal/database to exclude collisions with variable name db

Full Changelog: v3.18.0...v3.18.1