Make the horizontal bar appear in AnchoredArtists example.

ImportanceOfBeingErnest · web-flow · commit 5eaab3b36e41 · 2018-01-23T17:40:03.000+01:00
The `AnchoredSizeBar` should, according to its comment string 

&gt; Draw a horizontal bar with the size in data coordinate of the given
        axes. A label will be drawn underneath (center-aligned).

This bar is not drawn, because from matplotlib 2.0 on, patches do not have any edge assigned to them any more. While the facecolor is set to `"None"`, it is really the edgecolor, which should be set to some color (e.g. black). This PR fixes this such that a bar appears in the plot.
diff --git a/examples/misc/anchored_artists.py b/examples/misc/anchored_artists.py
@@ -34,7 +34,7 @@ def __init__(self, transform, size, label, loc,
         sep in points.
         """
         self.size_bar = AuxTransformBox(transform)
-        self.size_bar.add_artist(Rectangle((0, 0), size, 0, fc="none", lw=1.0))
+        self.size_bar.add_artist(Rectangle((0, 0), size, 0, ec="black", lw=1.0))
 
         self.txt_label = TextArea(label, minimumdescent=False)
 
