!20 improve generate-password usage

Merge pull request !20 from chenyanpanHW/generate-password

patch-tracking/patch_tracking/cli/generate_password

@@ -47,12 +47,11 @@ def password_strength_check(password):
 def usage():
     """ usage """
     print(
-        """usage:
-    generate_password PASSWORD
+        """usage: generate_password PASSWORD
 
-PASSWORD must be within the latin1 character set
-
-PASSWORD strength require:
+Requirements:
+1. PASSWORD must be within the 'latin1' character set
+2. PASSWORD strength require:
     6 characters or more
     at least 1 digit [0-9]
     at least 1 alphabet [a-z]
@@ -79,7 +78,8 @@ if __name__ == "__main__":
     password_ = sys.argv[1]
     err = latin1_encode(password_)
     if err:
-        print("password: outside the 'latin-1' character set range")
+        usage()
+        print("PASSWORD: outside the 'latin-1' character set range")
         sys.exit(1)
 
     ret = password_strength_check(password_)