changed target to iTarget (meaning int index of target)

to make all the subclasses of GraphicsLayer match

flatland/utils/graphics_layer.py

@@ -66,7 +66,7 @@ class GraphicsLayer(object):
     def get_cmap(self, *args, **kwargs):
         return plt.get_cmap(*args, **kwargs)
 
-    def setRailAt(self, row, col, binTrans, target=None):
+    def setRailAt(self, row, col, binTrans, iTarget=None):
         """ Set the rail at cell (row, col) to have transitions binTrans.
             The target argument can contain the index of the agent to indicate
             that agent's target is at that cell, so that a station can be

flatland/utils/render_qt.py

@@ -157,7 +157,7 @@ class QTSVG(GraphicsLayer):
         self.lwAgents = []
         self.agents_prev = []
 
-    def setRailAt(self, row, col, binTrans, target=None):
+    def setRailAt(self, row, col, binTrans, iTarget=None):
         if binTrans in self.track.dSvg:
             sSVG = self.track.dSvg[binTrans].to_string()
             svgWidget = create_QtSvgWidget_from_svg_string(sSVG)