This commit extends the same logic in the previous commit to the
comparison of offsets returned from the median time source in the tests.
In particular it modifies the tests to allow for the offsets to differ by
a second due to a boundary condition to prevent false positives.
The new median time tests perform a comparsion of the adjusted time
returned from the median time source to the expected value. However,
since time is always moving, it is possible the current time between the
call to the adjusted time function and the current time taken in the tests
for comparison just after the call differ by a second due to a boundary
condition. So, this commit modifies the tests to allow for this
condition.