NumbaDeprecationWarning: The 'nopython' keyword argument was not supplied to the 'numba.jit' decorator.

**Describe the bug**
Importing pyntcloud with numba 0.57.0 (and ostensibly 0.58.0) as well gives the following warning (repeated three times):

`NumbaDeprecationWarning: The 'nopython' keyword argument was not supplied to the 'numba.jit' decorator. The implicit default value for this argument is currently False, but it will be changed to True in Numba 0.59.0. See https://numba.readthedocs.io/en/stable/reference/deprecation.html#deprecation-of-object-mode-fall-back-behaviour-when-using-jit for details.`

This is because of the three `@njit` decorators in `pyntcloud/utils/numba.py` which do not have an explicit `nopython` argument passed to them.

**To Reproduce**
Import pyntcloud with numba 0.57.0 installed.

**Expected behavior**
No deprecation warning

**Desktop (please complete the following information):**
Both Windows 10 and multiple linux distributions; should be OS agnostic.