fix(scxml): makes scxml based sources render correctly again

[sverweij]

Description

• fix(parse/scxml): adds emitting id's for transitions (these id's are now necessary for proper rendition)
• fix(test): makes tests properly fail when schema validation fails
• fix(schema): makes the 'id' transition attribute mandatory

How Has This Been Tested?

• green ci
• updated automated non-regression tests

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Documentation only change
• Refactor (non-breaking change which fixes an issue without changing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• 📖

  • My change doesn't require a documentation update, or ...
  • it does and I have updated it

• ⚖️

  • The contribution will be subject to The MIT license, and I'm OK with that.
  • The contribution is my own original work.
  • I am ok with the stuff in CONTRIBUTING.md.

[codeclimate]

Code Climate has analyzed commit df40c57 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (100% is the threshold).

This pull request will bring the total coverage in the repository to 100.0% (0.0% change).

View more on Code Climate.