ModelEvaluator has calls to outdated methods

[hemanklamba]

l_t[0].plot_score_distribution(figsize=params.figsize)

returns

AttributeError with the following message:
AttributeError: 'Rectangle' object has no property 'normed'

On more digging, it seems that "normed" property has been deprecated and needs to be replaced.

[nanounanue]

Culprit line:

triage/src/triage/component/postmodeling/contrast/model_evaluator.py

Lines 367 to 371 in e47f07a

	plt.hist(df_.score,
	bins=nbins,
	normed=True,
	alpha=0.5,
	color='blue')

From the docs:

normed : bool, optional

    Deprecated; use the density keyword argument instead.