Update app.py

app.py

@@ -4,7 +4,7 @@ import bar_chart_race as bcr
 import base64
 
 df = bcr.load_dataset("covid19_tutorial")
-html_str = bcr.bar_chart_race(df=df).data
+html_str = bcr.bar_chart_race(df=df)
 
 start = html_str.find('base64,')+len('base64,')
 end = html_str.find('">')