v0.6.0 dbt_snapchat_ads_source

PR #20 includes the following updates:

Feature update 🎉

• Unioning capability! This adds the ability to union source data from multiple snapchat_ads connectors. Refer to the Union Multiple Connectors README section for more details.

Under the hood 🚘

• Updated tmp models to union source data using the fivetran_utils.union_data macro.
• To distinguish which source each field comes from, added source_relation column in each staging model and applied the fivetran_utils.source_relation macro.
• Updated tests to account for the new source_relation column.

PR #17 includes the following updates:

• Incorporated the new fivetran_utils.drop_schemas_automation macro into the end of each Buildkite integration test job.
• Updated the pull request templates.

Full Changelog: v0.5.0...v0.6.0