refactor: render relationship test on defining model

[mascah]

resolves #181

Description

Currently a relationship test is rendered on the model that the test points "to".
This change reverses the direction so that the relationship test renders on the model
that the test is defined in, or the "from" model pointing to the parent model.

schema.yml

version: 2

models:
    - name: my_first_dbt_model
      description: "A starter dbt model"
      columns:
          - name: id
            description: "The primary key for this table"
            tests:
                - unique
                - not_null

    - name: my_second_dbt_model
      description: "A starter dbt model"
      columns:
          - name: id
            description: "The primary key for this table"
            tests:
                - unique
                - not_null
                - relationships:
                    to: ref('my_first_dbt_model')
                    field: id

Checklist

• I have signed the CLA
• I have generated docs locally, and this change appears to resolve the stated issue
• I have updated the CHANGELOG.md and added information about my change to the "dbt next" section.

[jtcohen6]

This looks great, thanks @mascah! Could you also add yourself as a contributor in the changelog? (See previous versions for examples)

I'll follow up with another PR that adds a relationships test to one of the models in the ci-project, so that we can have this appear in our PR deploy-preview site.

[mascah]

This looks great, thanks @mascah! Could you also add yourself as a contributor in the changelog? (See previous versions for examples)

Done!

I'll follow up with another PR that adds a relationships test to one of the models in the ci-project, so that we can have this appear in our PR deploy-preview site.

Just noticed that it looks like one already exists, hopefully this covers what you were thinking and saves you the time!

https://github.com/fishtown-analytics/dbt-docs/blob/97570c58c474dfbba0b145576792bc8e3ead6c5c/ci-project/models/marts/core/schema.yml#L49-L51

[jtcohen6]

Just noticed that it looks like one already exists, hopefully this covers what you were thinking and saves you the time!

Well spotted! Even better.

LGTM, thanks @mascah!