Chat with Vendor/Customer

Delivery boy can now chat with vendor or customer.
To use the feature, you will need to make a small change/configuration to some files in the Delivery boy flutter app.
You need to set your firebase server key to be able to allow message to be sent to vendor/customer.
Go to [PROJECT_FOLDER] > lib > constants > app_strings.dart, you will see a variable called firebaseServerToken.
Change the value for that variable to your the server key gotten from your firebase project.
static String firebaseServerToken = "YOUR_FIREBASE_PROJECT_SERVER_KEY";