Improve Aggregated Log Output with additional getters (#39)

[MikeDabrowski]

• Please check if the PR fulfills these requirements

• [x] The commit message follows our guidelines
• [x] Tests for the changes have been added (n/a)
• [x] Docs have been added / updated (n/a)

• What kind of change does this PR introduce? Following the discussion in #39 I debugged the issue with brief-reporter. Two getters were missing.

• What is the current behavior? #39 - Brief fails because it receives undefined from karma-parallel

• What is the new behavior (if this is a feature change)? The output log object contains two additional getters for success and for skipped tests. No other changes.

• Does this PR introduce a breaking change? No

• Other information: I don't feel the need to add tests for that, but if maintainers ever look at this PR and find it worthy, just drop me a line and I'll try to add some.