Support dbt 1.0.0

[jaypeedevlin]

Per the release notes for 1.0.0rc1:

In v1.0.0, pip install dbt will raise an explicit error. Instead, please use pip install dbt-<adapter> (to use dbt with that database adapter), or pip install dbt-core (for core functionality). For parity with the previous behavior of pip install dbt, you can use: pip install dbt-core dbt-postgres dbt-redshift dbt-snowflake dbt-bigquery (dbt-labs/dbt-core#4100, #4133)

In order to support >= 1.0.0 we need to add logic around this change.

[NiallRees]

You cool taking this on?

[jaypeedevlin]

Yep, I may need some support but thinking this will be the start of my contributions to the project.