Add subscription item ID

[LewisDavies]

Pull Request Are you a current Fivetran customer? Lewis Davies, Senior Analytics Engineer, Prisma

What change(s) does this PR introduce? Adds subscription_item_id column to stripe__invoice_line_items, allowing the model to be joined to Stripe Usage Records.

Did you update the CHANGELOG?

• [x] Yes

Does this PR introduce a breaking change?

• [ ] Yes (please provide breaking change details below.)
• [x] No (please provide an explanation as to how the change is non-breaking below.) It simply brings through a column that already exists in an upstream model.

Did you update the dbt_project.yml files with the version upgrade (please leverage standard semantic versioning)? (In both your main project and integration_tests)

• [x] Yes

Is this PR in response to a previously created Bug or Feature Request

• [ ] Yes, Issue/Feature [link bug/feature number here]
• [x] No

How did you test the PR changes?

• [ ] CircleCi
• [x] Local (please provide additional testing details below) I made the changes on my machine and installed the local version in my dbt project by adding - local: ~/dbt_stripe to packages.yml. I then successfully ran dbt build -s package:stripe.

Select which warehouse(s) were used to test the PR

• [ ] BigQuery
• [ ] Redshift
• [x] Snowflake
• [ ] Postgres
• [ ] Databricks
• [ ] Other (provide details below)

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:dancer: **Feedback** We are so excited you decided to contribute to the Fivetran community dbt package! We continue to work to improve the packages and would greatly appreciate your [feedback](https://www.surveymonkey.com/r/DQ7K7WW) on our existing dbt packages or what you'd like to see next.

[fivetran-joemarkiewicz]

Hi @LewisDavies thanks for opening this PR!

I believe the addition of the subscription_item_id to the stripe__invoice_line_item table makes sense to me and could be leveraged by others. In addition to your updates already in the PR, would you be able to include this field in the stripe.yml documentation for this model?

Once you apply that update, I believe this may look good to move forward!

[LewisDavies]

FYI @fivetran-joemarkiewicz Docs have been updated now

[fivetran-joemarkiewicz]

@LewisDavies we will most likely be cutting a new release come Monday. I hope to get it out sooner, but we prefer to not cut releases on Friday's. You can follow the PR #52 for status on the merge and release of your changes to the package!