Cuda Python : AttributeError: module 'cffi' has no attribute 'FFI'

I am new to cuda and have followed instructions here-

GPU - geforce 940mx
cudatoolkit - 8.0
numba - 0.37.0
python - 3.6.5

I tried to setup my environment exactly as per the video (Installing CUDA Python), but when I try to run the sample program I get this error:

PS D:\workspace\random-git-repos\cudacasts> D:/apps/Anaconda3/envs/pgpu/python.exe d:/workspace/random-git-repos/cudacasts/InstallingCUDAPython/
Traceback (most recent call last):
  File "d:/workspace/random-git-repos/cudacasts/InstallingCUDAPython/", line 26, in <module>
  File "d:/workspace/random-git-repos/cudacasts/InstallingCUDAPython/", line 17, in main
    C = VectorAdd(A, B)
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\cuda\", line 88, in __call__
    return, args, kws)
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\npyufunc\", line 291, in call
    cr.launch(func, shape[0], stream, devarys)
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\cuda\", line 197, in launch
    func.forall(count, stream=stream)(*args)
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\cuda\", line 249, in __call__
    kernel = self.kernel.specialize(*args)
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\cuda\", line 712, in specialize
    [self.typingctx.resolve_argument_type(a) for a in args])
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\cuda\", line 712, in <listcomp>
    [self.typingctx.resolve_argument_type(a) for a in args])
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\typing\", line 290, in resolve_argument_type
    return typeof(val, Purpose.argument)
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\typing\", line 28, in typeof
    ty = typeof_impl(val, c)
  File "D:\apps\Anaconda3\envs\pgpu\lib\", line 803, in wrapper
    return dispatch(args[0].__class__)(*args, **kw)
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\typing\", line 46, in typeof_impl
    from . import cffi_utils
  File "D:\apps\Anaconda3\envs\pgpu\lib\site-packages\numba\typing\", line 17, in <module>
    ffi = cffi.FFI()
AttributeError: module 'cffi' has no attribute 'FFI'