Bump to v0.6.0

[jtcohen6]

resolves #31

v0.6.0 will:

• Include v1 compatibility changes (Rename data/ to seeds/ #28 + Updating to match current file path naming schemes. #29) and require dbt-core>=1.0.0b1
• Also include change from Rewrite data tests to support more SQL dialects #21 (we never cut v0.5.2)
• Exclude the dbt_adapter_tests package. This was an experiment in seeing if we could package up our integration testing scaffold, for use in adapter plugins external to core. There is absolutely still a need for this, but it should come after significant refactor/rewrite of our testing scaffold. I feel comfortable removing the package at this point: we never documented it; we only ever used it in the dbt-spark plugin, and that plugin has since migrated off of its use

TODO after merging + pushing to PyPi: Update dbt-spark dev requirements