Fix depth

[paulz]

Goal

Fixes #357

Design

Use top level dictionary to store depth

Changeset

Extracted report tests into a separate file

Tests

Unit test
Load report test

Mazerunner tests are failing and probably need update, please help, @kattrali

Review

Outstanding Questions

• Added a changelog entry? Not yet

• This pull request is ready for:
  • Initial review of the intended approach, not yet feature complete
  • Structural review of the classes, functions, and properties modified
  • Final review

• The correct target branch has been selected (master for fixes, next for
  features)
• Consistency across platforms for structures or concepts added or modified
• Consistency between the changeset and the goal stated above
• Internal consistency with the rest of the library - is there any overlap between existing interfaces and any which have been added?
• Usage friction - is the proposed change in usage cumbersome or complicated?
• Performance and complexity - are there any cases of unexpected O(n^3) when iterating, recursing, flat mapping, etc?
• Concurrency concerns - if components are accessed asynchronously, what issues will arise
• Thoroughness of added tests and any missing edge cases
• Idiomatic use of the language

[kattrali]

The test failures on CI look like they need the test assertions to be updated. The tests are verifying the length of the stacktrace which is directly affected by changes to depth.

[kattrali]

Closing in favor of #363