Travis: Build perl 5.19
Setup authorized_keys for tests
Raw.xs: Return the underlying credentials object
Cred.xs: A passphrase for the private key is optional
10-clone.t: Added sshkey() test case
Raw.xs: Set G_EVAL when invoking the credentials callback.
10-clone.t: Added tests for bad credentials
Raw.xs: Plug call_sv leaks
Raw.xs: Introduce git_ensure_pv
Cred.xs: Perform stricter type validation
Change: update (closes #90)