make mulify work also for 3d plots

pymule/mule.py

@@ -139,11 +139,20 @@ def mulify(fig):
             (np.array([1/1.3,-1])*vertices+55.)/550.+np.array([0.13,0.66]),
             commands
         ),
-        fc="none", ec='gray', transform=fig.transFigure
-    )
-    ax.add_patch(pp1)
-    ax.text(
-        0.21, 0.69,
-        "$\\small\\textsc{McMule}$",
-        transform=fig.transFigure, ha='center',va='top', color='gray'
+        fc="none", ec='gray', transform=fig.transFigure, zorder=100000
     )
+
+    if '3D' in str(type(ax)):
+        fig.patches.append(pp1)
+        fig.text(
+            0.21, 0.69,
+            "$\\small\\textsc{McMule}$",
+            transform=fig.transFigure, ha='center',va='top', color='gray'
+        )
+    else:
+        ax.add_patch(pp1)
+        ax.text(
+            0.21, 0.69,
+            "$\\small\\textsc{McMule}$",
+            transform=fig.transFigure, ha='center',va='top', color='gray'
+        )