test/geo-point: relax too precise assertions

Relax the assertions to verify only the integer part of the distances.
The decimal part is subject to small variances depending on the exact
implementation of floating-point arithmetic.

For example, the distance calculated on Node v0.11.13 is different
than the distance calculated on Node v0.10.x.
Merge pull request #264 from strongloop/feature/fix-precision-in-tests-for-v0-11

relax too precise assertions in test/geo-point