WIP tests for ColdSignal.startWithSink()
Finish testing ColdSignal.startWithSink
Add == over Event<T>
Test basic ColdSignal constructors
Test ColdSignal.fromValues
Test ColdSignal.fromResult
Test ColdSignal.mapAccumulate
Fix mapAccumulate tests
Test ColdSignal.filter
Test ColdSignal.map
Test ColdSignal.scan
Test ColdSignal.reduce
Test ColdSignal.combinePrevious
Test ColdSignal.skip
Test ColdSignal.skipRepeats
Test ColdSignal.skipWhile
Test ColdSignal.take
Test ColdSignal.takeLast
Test ColdSignal.takeWhile
Test ColdSignal.takeUntil