This change adds `NewCredentialSSHKeyFromSigner`, which allows idiomatic
use of SSH keys from Go. This also lets us spin off an SSH server in the
tests.
(cherry picked from commit abf02bc7d7)
This is compliant with
https://github.com/golang/go/wiki/Modules#releasing-modules-v2-or-higher,
which says
```
Major branch: Update the go.mod file to include a /v3 at the end of the
module path in the module directive (e.g., module
github.com/my/module/v3). Update import statements within the module to
also use /v3 (e.g., import "github.com/my/module/v3/mypkg"). Tag the
release with v3.0.0.
```
This also means that unfortunately we cannot keep using libgit2's exact
version number (plus a build number for git2go purposes, since go only
recognizes vMAJOR.MINOR.PATCH format).
(Tentatively) fixes: #536
This change adds a `go.mod` file. An empty file is sufficient since this
project has no external dependencies. For people that want to use the static
version of libgit2, this module can be vendored and the following can be added
to their `go.mod` file:
replace github.com/libgit2/git2go => ./vendor/github.com/libgit2/git2go
lhchavez