np.bool deprecated in Numpy >= 1.20

[xchoo]

When using NengoOCL with Numpy >= 1.20, the following error can occur:

Traceback (most recent call last):
  File "run_spaun.py", line 748, in <module>
    sim = nengo_ocl.Simulator(model, dt=cfg.sim_dt, context=ctx,
  File "/home/xchoo/miniconda3/envs/spaun/lib/python3.8/site-packages/nengo_ocl/simulator.py", line 363, in __init__
    plans.extend(self._plan_op_group(op_type, op_list))
  File "/home/xchoo/miniconda3/envs/spaun/lib/python3.8/site-packages/nengo_ocl/simulator.py", line 742, in _plan_op_group
    return getattr(self, "_plan_" + op_type.__name__)(ops)
  File "/home/xchoo/miniconda3/envs/spaun/lib/python3.8/site-packages/nengo_ocl/simulator.py", line 867, in _plan_Copy
    if any(dupl(i) for i in xinds) or any(dupl(i) for i in yinds):
  File "/home/xchoo/miniconda3/envs/spaun/lib/python3.8/site-packages/nengo_ocl/simulator.py", line 867, in <genexpr>
    if any(dupl(i) for i in xinds) or any(dupl(i) for i in yinds):
  File "/home/xchoo/miniconda3/envs/spaun/lib/python3.8/site-packages/nengo_ocl/simulator.py", line 864, in <lambda>
    and not (isinstance(s, np.ndarray) and s.dtype == np.bool)
  File "/home/xchoo/miniconda3/envs/spaun/lib/python3.8/site-packages/numpy/__init__.py", line 305, in __getattr__
    raise AttributeError(__former_attrs__[attr])
AttributeError: module 'numpy' has no attribute 'bool'.
`np.bool` was a deprecated alias for the builtin `bool`. To avoid this error in existing code, use `bool` by itself. Doing this will not modify any behavior and is safe. If you specifically wanted the numpy scalar type, use `np.bool_` here.
The aliases was originally deprecated in NumPy 1.20; for more details and guidance see the original release note at:
    https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations

Changing np.bool to bool seems to rectify this issue with no (apparent) side-effects.