Try again to fix Travis legend bug

Author: lukelbd

proplot/wrappers.py

@@ -87,6 +87,24 @@ def _load_objects():
 }
 
 
+def _get_renderer(fig):
+    """Get renderer for calculating the legend bounding box for centered-row
+    legends. This is copied from tight_layout.py in matplotlib."""
+    # NOTE: This will be removed when #74 is done
+    if fig._cachedRenderer:
+        renderer = fig._cachedRenderer
+    else:
+        canvas = fig.canvas
+        if canvas and hasattr(canvas, 'get_renderer'):
+            renderer = canvas.get_renderer()
+        else:
+            warnings.warn('Falling back to Agg renderer.')
+            from matplotlib.backends.backend_agg import FigureCanvasAgg
+            canvas = FigureCanvasAgg(fig)
+            renderer = canvas.get_renderer()
+    return renderer
+
+
 def default_latlon(self, func, *args, latlon=True, **kwargs):
     """
     Wraps %(methods)s for `~proplot.axes.BasemapAxes`.
@@ -2453,10 +2471,7 @@ def legend_wrapper(
             legs[0].set_frame_on(True)  # easy!
         else:
             # Get coordinates
-            if hasattr(self.figure.canvas, 'get_renderer'):
-                renderer = self.figure.canvas.get_renderer()
-            else:
-                renderer = self.figure._cachedRenderer
+            renderer = _get_renderer(self.figure)
             bboxs = [leg.get_window_extent(renderer).transformed(
                 self.transAxes.inverted()) for leg in legs]
             xmin, xmax = min(bbox.xmin for bbox in bboxs), max(