postgres_utils 2.0.0-rc.6

A few utils for working with postgresql databases.

2.0.0-rc.6

• Require postgres ^3.5.0; remove the postgres/src implementation import.
• Remove CustomTypeBind; CustomBind no longer takes a type.
• Replace the discontinued pedantic lint set with lints recommended.
• Add a dockerized smoke test (test/smoke_test.dart).

2.0.0-rc.5

• Migrate to postgres v3.
• Add concatColumns to OnConflictActionDoUpdate for allowing incremental updates in upset.

1.0.0

• Initial version.