Update binary_material notebook to include coeff plot.

Address issue #108

A plot that contains three sets of influence coefficients was added. The
first set of the influence coefficients are calibrated using 31 x 31 delta
microstructures. The second set are the influence coefficients mentioned
above after they have been zero padded to 93 x 93, and the last set of
coefficients were calibrated using 93 x 93 delta microstructures. This plot
was added to generate discussion to hopefully resolve the current issue.
Added zero padding in frequency space

Address issue #108

The resize_coeff method now takes a scale factor and instead of the size of the
desired array. Currently the scale factors must be integer values. This for of
zero padding call spectral interpolation should persevere the general shape of
the influence coefficients when they are scaled to a larger domain. Currently the influence coefficients can only be scaled by an integer value.