refactor app.py and requirements.txt to specify gradio version

app.py

@@ -43,7 +43,7 @@ iface = gr.Interface(
          gr.Textbox(label="Interpretation")
      ],
      title="TinyFinBERT Sentiment Analysis",
-     allow_api=True,
+     #allow_api=True,
      api_name="predict"
 )