Maintain backward compatibility with old mesa viz API

mesa/__init__.py

@@ -5,9 +5,9 @@
 """
 import datetime
 
-import mesa.flat.visualization as visualization
 import mesa.space as space
 import mesa.time as time
+import mesa.visualization as visualization
 from mesa.agent import Agent
 from mesa.batchrunner import batch_run
 from mesa.datacollection import DataCollector

mesa/visualization/ModularVisualization.py

@@ -0,0 +1 @@
+from mesa_viz_tornado.ModularVisualization import *  # noqa

mesa/visualization/TextVisualization.py

@@ -0,0 +1 @@
+from mesa_viz_tornado.TextVisualization import *  # noqa

mesa/visualization/UserParam.py

@@ -0,0 +1 @@
+from mesa_viz_tornado.UserParam import *  # noqa

mesa/visualization/__init__.py

@@ -0,0 +1,4 @@
+from mesa_viz_tornado.ModularVisualization import *  # noqa
+from mesa_viz_tornado.modules import *  # noqa
+from mesa_viz_tornado.UserParam import *  # noqa
+from mesa_viz_tornado.TextVisualization import *  # noqa

mesa/visualization/modules.py

@@ -0,0 +1 @@
+from mesa_viz_tornado.modules import *  # noqa