fix: use first github release in the list as latest when latest is not available

[matheuscscp]

Hi @marcosnils!

I wasn't being able to install or update github.com/weaveworks/tf-controller, so I found this fallback solution for GitHub latest releases which fixes the problem for this repo. The repo does not publish a "latest reference" release, which is what GetLatestRelease() looks for. But GitHub has this ListReleases() paginated API which lists all the releases starting from the latest (in the common sense meaning of the word, not the "latest reference").

Kind regards,

[matheuscscp]

oh, sounds like this is a duplicate of #87

and relates to #86

[marcosnils]

closing since this didn't get too much traction and it has been stale for a while