Add comment about write privileges in EnsureSchema

Added comment to clarify permissions needed for EnsureSchema function.

Author: andrew-corbalt

migrations/migration.go

@@ -245,6 +245,7 @@ func Migrate(db *sqlx.DB, migrations []NamedMigration) error {
 	}
 }
 
+// This function requires write privleges even if the schema already exists
 func EnsureSchema(db *sqlx.DB, schemaName string) error {
 	q := fmt.Sprintf("CREATE SCHEMA IF NOT EXISTS %s", schemaName)
 	_, err := db.Exec(q)