hashicorp/serf is only required as a dependency of hashicorp/consul so
bumping the version has no direct consequence for Prometheus itself. The
net gain is that we don't depend anymore on launchpad.net/gocheck which
required the bzr binary to be installed.
Signed-off-by: Simon Pasquier <spasquie@redhat.com>
Most fixes here are mostly http2, but since I'm suspecting a bug in
the context package, I thought we better go with the current version
to rule out bugs already fixed.