Use Golang 1.5.1 for all installations from source in GitLab 8.1

The update/installation instructions for 8.0 told people to get Golang 1.5.0 for some time. There seems to be a security fix in Golang 1.5.1 (not very clear). To be sure, I think source users should install golang 1.5.1 or newer and recompile gitlab-git-http-server when they upgrade to 8.1.

Milestone changed to 8.6

@jacobvosmaer I've moved this to 8.6. Please close if it's no longer relevant.

Looking at the Go 1.5 minor version release notes I do not see any mention of the net/http security issue.

https://golang.org/doc/devel/release.html#go1.5.minor

There was another issue, fixed in 1.5.3, affecting the TLS stack but we don't use that in gitlab-workhorse.

Let's close this.

Status changed to closed

mentioned in merge request !14785