The default reporter used when expect_that() is run interactively.
It responds by displaying a summary of the number of successes and failures
and stop()ping on if there are any failures.
Other reporters:
CheckReporter,
DebugReporter,
FailReporter,
JunitReporter,
ListReporter,
LocationReporter,
MinimalReporter,
MultiReporter,
ProgressReporter,
RStudioReporter,
Reporter,
SilentReporter,
SlowReporter,
SummaryReporter,
TapReporter,
TeamcityReporter