I recently added a signing subkey, which is used to sign gitian
asserts as well as commits.
Old:
```
pub rsa2048/0x74810B012346C9A6 2011-08-24
uid Wladimir J. van der Laan <laanwj@gmail.com>
sub rsa2048/0xF69705ED890DE427 2011-08-24
```
New:
```
pub rsa2048/0x74810B012346C9A6 2011-08-24 [expires: 2019-02-14]
uid Wladimir J. van der Laan <laanwj@visucore.com>
uid Wladimir J. van der Laan <laanwj@gmail.com>
sub rsa2048/0xF69705ED890DE427 2011-08-24
sub rsa2048/0x1E4AED62986CD25D 2017-05-17 [expires: 2019-05-17]
sub rsa2048/0x69B4C4CDC628F8F9 2017-05-17 [expires: 2019-05-17]
```