* Update AUTHORS and CONTRIBUTORS

* Fix WSL self-test failures

Some of the benchmark self-tests expect and check for a particular
output format from the benchmark library. The numerical values must
not be infinity or not-a-number, or the test will report an error.
Some of the values are computed bytes-per-second or items-per-second
values, so these require that the measured CPU time for the test to be
non-zero. But the loop that is being measured was empty, so the
measured CPU time for the loop was extremely small. On systems like
Windows Subsystem for Linux (WSL) the timer doesn't have enough
resolution to measure this, so the measured CPU time was zero.

This fix just makes sure that these tests have something within the
timing loop, so that the benchmark library will not decide that the
loop takes zero CPU time. This makes these tests more robust, and in
particular makes them pass on WSL.