lalinference postprocess is not compatible with the most updated scipy.

cbcBayesPostProc for ROQ mcmc runs return the following error.

Traceback (most recent call last):
  File "/home/emfollow-playground/.local/bin/cbcBayesPostProc", line 1313, in <module>
    greedy=not(opts.kdecredibleregions)
  File "/home/emfollow-playground/.local/bin/cbcBayesPostProc", line 619, in cbcBayesPostProc
    bppu.plot_calibration_pos(pos, outpath=outdir)
  File "/home/emfollow-playground/.local/lib/python3.6/site-packages/lalinference/bayespputils.py", line 6940, in plot_calibration_pos
    plot_spline_pos(logfreqs, amp, color=color, level=level, label="{0} (mean, {1}%)".format(ifo.upper(), int(level*100)))
  File "/home/emfollow-playground/.local/lib/python3.6/site-packages/lalinference/bayespputils.py", line 6902, in plot_spline_pos
    temp = interpolate.spline(logf, samp, np.log(fs))
AttributeError: module 'scipy.interpolate' has no attribute 'spline'

This is the attribute is not there for scipy==1.3.0.

cc: @cjhaster @vivien