我有一个git的问题。当我推动回购时，结果是：
piero@jarvis:~/~dev/secure-password$ git commit -m 'Initial commit with contributors'
[master (root-commit) faf8365] Initial commit with contributors
1 file changed, 1 insertion(+)
create mode 100644 contributors.txt
piero@jarvis:~/~dev/secure-password$ git push -u origin master
Agent admitted failure to sign using the key.
Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
piero@jarvis:~/~dev/secure-password$