added table model for wallet feature branch

app/models.py

@@ -51,3 +51,8 @@ class Bids(db.Model):
     buyer = db.Column(db.Integer)
     bid_price = db.Column(db.Float)
     bid_date = db.Column(db.DateTime(timezone=True), default=func.now()) 
+
+class Wallet(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    user_id = db.Column(db.Integer)
+    amount = db.Column(db.Float)