energy calculation #25

Hello,
In the 'as_spectral' function, at the line
energy = np.multiply(energy, spectrum), shouldn't it be
energy = np.multiply(1/16*energy, spectrum) ?

Indeed, since the Jonswap spectrum is calculated for Hm0 = 1, we need to update the Johnswap value by multiplying the calculated Jonswap by the true Hm0**2, ie energy/16.

I'm not sure of what I'm saying, it just appears the values obtain for energy = np.multiply(1/16*energy, spectrum) are more realistic than those obtained with the curent implementation.