Add password prompt

Add prompt for password if the user didn't specify it using the
-p/--password option

huami_token.py

@@ -7,6 +7,7 @@ import shutil
 import urllib
 import argparse
 import requests
+import getpass
 
 from rich.console import Console
 from rich.table import Column, Table
@@ -241,6 +242,9 @@ if __name__ == "__main__":
     table.add_column("MAC", style="dim", width=17, justify='center')
     table.add_column("auth_key", width=50, justify='center')
 
+    if args.password is None:
+        args.password = getpass.getpass()
+
     device = HuamiAmazfit(method=args.method,
                           email=args.email,
                           password=args.password)