Add more tolerance to UnitTestParametricCoordinates

I noticed a failure in a dashboard run of UnitTestParametricCoordinates. This test uses randomly generated numbers to test the behavior of some cell shapes, and there was an instance that occured with seed 1447261681 that caused one of the comparisons to be just slightly larger than the default tolerance but still within reasonable value.

I just increased the tolerance of that particular comparison. Hopefully this will prevent all future failures.