Bug Fix: Coalesce incremental fields

[fivetran-avinash]

PR Overview

This PR will address the following Issue/Feature: [#86]

This PR will result in the following new package version: v0.13.1

No field names were changed, just the underlying behavior for null coalesces.

Please provide the finalized CHANGELOG entry which details the relevant changes included in this PR:

Bug Fixes

• Coalesces the backfill_lifetime_sums fields from incremental loads, as well as cohort_month_number in the rare cases there are no orders from an incremental period. This fixes the issue of NULL values in the lifetime columns in shopify__customer_cohorts table. (PR #86).

Under the Hood:

• Added consistency and integrity tests within integration_tests for the shopify__customer_cohorts model.

PR Checklist

Basic Validation

Please acknowledge that you have successfully performed the following commands locally:

• dbt run –full-refresh && dbt test
• dbt run (if incremental models are present) && dbt test (customer)

Before marking this PR as "ready for review" the following have been applied:

• The appropriate issue has been linked, tagged, and properly assigned
• All necessary documentation and version upgrades have been applied
• docs were regenerated (unless this PR does not include any code or yml updates)
• BuildKite integration tests are passing
• Detailed validation steps have been provided below

Detailed Validation

Please share any and all of your validation steps:

Customer validated that the incremental run worked as expected internally.

We created validation tests as well on the end model impacted, and were able to get a successful pass on our integration tests data.

If you had to summarize this PR in an emoji, which would it be?

🏃🏽

[fivetran-catfritz]

@fivetran-avinash I saw that the customer tested this change, but should we do our own validation?

[fivetran-catfritz]

lgtm for release!