Background color for cell id.

plot_transmission_timeline.py

     cmap = matplotlib.cm.get_cmap("Set3")
     for c in transmission_df["cellID"].unique():
         bounds = transmission_df[["index", "cellID"]].groupby("cellID").agg(["min", "max"]).loc[c]
-        host.axvspan(bounds.min(), bounds.max() + 1, alpha=0.3, color=cmap.colors[c])
+        host.axvspan(bounds.min(), bounds.max(), alpha=0.3, color=cmap.colors[c])
 
     plt.subplots_adjust()