Show commit hash of Siren

[chong-he]

It would be nice to show the commit hash of Siren. This is particularly useful during testing phase to be sure that the version being run on is of a particular commit hash

[chong-he]

A follow up on this is, it would be great if Siren can display the commit hash when checking the version (Siren --version or something like that). Currently, if I understand correctly, there is no way of checking the commit hash