Make provider errcheck clean

[sean-]

https://travis-ci.org/terraform-providers/terraform-provider-postgresql

17.10s$ make test
==> Checking that code complies with gofmt requirements...
==> Checking for unchecked errors...
==> Installing errcheck...
Unchecked errors found in the following places:
postgresql/resource_postgresql_database.go:119:18:	defer conn.Close()
postgresql/resource_postgresql_database.go:220:18:	defer conn.Close()
postgresql/resource_postgresql_database.go:256:18:	defer conn.Close()
postgresql/resource_postgresql_database.go:284:18:	defer conn.Close()
postgresql/resource_postgresql_database.go:341:18:	defer conn.Close()
postgresql/resource_postgresql_extension.go:63:18:	defer conn.Close()
postgresql/resource_postgresql_extension.go:98:18:	defer conn.Close()
postgresql/resource_postgresql_extension.go:127:18:	defer conn.Close()
postgresql/resource_postgresql_extension.go:157:18:	defer conn.Close()
postgresql/resource_postgresql_extension.go:181:18:	defer conn.Close()
postgresql/resource_postgresql_role.go:151:18:	defer conn.Close()
postgresql/resource_postgresql_role.go:264:18:	defer conn.Close()
postgresql/resource_postgresql_role.go:270:20:	defer txn.Rollback()
postgresql/resource_postgresql_role.go:311:18:	defer conn.Close()
postgresql/resource_postgresql_role.go:339:18:	defer conn.Close()
postgresql/resource_postgresql_role.go:397:18:	defer conn.Close()
postgresql/resource_postgresql_schema.go:163:18:	defer conn.Close()
postgresql/resource_postgresql_schema.go:169:20:	defer txn.Rollback()
postgresql/resource_postgresql_schema.go:196:18:	defer conn.Close()
postgresql/resource_postgresql_schema.go:202:20:	defer txn.Rollback()
postgresql/resource_postgresql_schema.go:231:18:	defer conn.Close()
postgresql/resource_postgresql_schema.go:259:18:	defer conn.Close()
postgresql/resource_postgresql_schema.go:312:18:	defer conn.Close()
postgresql/resource_postgresql_schema.go:318:20:	defer txn.Rollback()
Please handle returned errors. You can check directly with `make errcheck`
make: *** [errcheck] Error 1