KelbowVisualizer: The letters in the Legend Label are smushed together (missing spacing)

[lwgray]

Describe the issue
A clear and concise description of what the bug is.
In the Kelbow visualizer I found that the Spacing between letters in the legend are absent. I also found this to be the case in the example visualization for Kelbow in both the latest and develop version of the docs. See image below
To Reproduce

from sklearn.datasets import make_blobs
from sklearn.preprocessing import StandardScaler
from sklearn.cluster import KMeans

from yellowbrick.cluster import KElbowVisualizer

# Generate sample data
centers = [[1, 1], [-1, -1], [1, -1]]
X, labels_true = make_blobs(n_samples=1500, centers=centers, cluster_std=0.3,
                            random_state=0)

Z = StandardScaler().fit_transform(X)
viz = KElbowVisualizer(KMeans())

viz.fit(Z)
viz.show()

Dataset
Did you use a specific dataset to produce the bug? Where can we access it?
yes... generated in the above code

Expected behavior
A clear and concise description of what you expected to happen.
I expect to see "elbow at k = 3, score = 264.727"

Desktop (please complete the following information):

• OS: [e.g. macOS] MacOS
• Python Version [e.g. 2.7, 3.6, miniconda] 3.7
• Yellowbrick Version [e.g. 0.7] 1.1

Additional context
Add any other context about the problem here.

@DistrictDataLabs/team-oz-maintainers