Milestone 1.3.0

[Scrum]

Proposed Changes

Describe the big picture of your changes here to communicate to the maintainers
why we should accept this pull request. If it fixes a bug or resolves a feature
request, be sure to link to that issue.

Types of Changes

What types of changes does your code introduce
Put an x in the boxes that apply

• Bug (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature which changes existing functionality)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating
the PR. If you're unsure about any of them, don't hesitate to ask. We're here to
help! This is a reminder of what we are going to look for before merging your
code.

• I have read the CONTRIBUTING guide
• Lint and unit tests pass with my changes
• I have added tests that prove my fix is effective/works
• I have added necessary documentation (if appropriate)
• Any dependent changes are merged and published in downstream modules

Further Comments

If this is a large or complex change, kick off the discussion by explaining why
you chose the solution you did and what alternatives you considered, etc...

Reviewers: @mrmlnc, @jescalan, @michael-ciniawsky, @posthtml/collaborators

[coveralls]

Coverage remained the same at 97.423% when pulling 38ecddc on milestone-1.3.0 into bcdb13a on master.