input: Write a python function to compute the Fourier transform of a given signal using scipy's fft function.
  assert all(abs(fourier_transform([0, 1, 0, 0]) - [1.+0.j, 0.-1.j, -1.+0.j, 0.+1.j]) < 1e-8)
  assert all(abs(fourier_transform([1, 1, 1, 1]) - [4.+0.j, 0.+0.j, 0.+0.j, 0.+0.j]) < 1e-8)
  assert all(abs(fourier_transform([0, 0, 0, 1]) - [1.+0.j, -1.+0.j, 1.+0.j, -1.+0.j]) < 1e-8)
output: from scipy.fft import fft
  
  def fourier_transform(signal):
      return fft(signal)