Feature: Union schema compatibility

[fivetran-catfritz]

Issue: #29

Confirm the following files were correctly updated automatically:

• CHANGELOG
• README
• stg_pinterest_ads.yml, src_pinterest_ads.yml, pinterest_ads.yml (depending if source or transform)
• docs.md
• joins
• window functions (partition by)
• 'source_relation' column added in staging and transform models
• tests

Manual updates:

• Add source_relation to downstream models if necessary
• Finish any incomplete/incorrect joins/partitions
• Update tests to include source_relation in unique-combination-of-cols if necessary
  • May need to remove some uniqueness tests in favor of the combo test

Validation:

• dbt run locally passes
• dbt test locally passes

[fivetran-catfritz]

Note--updated fivetran_utils.union_data to account for pinterest naming exceptions.

[fivetran-joemarkiewicz]

Approving these changes with the stipulation of the upstream pinterest_source updates being applied and approved. In addition there are a few notes below I would like you to address before rolling out these updates along with the others.