Squashed '_vendor/src/github.com/prometheus/client_golang/' content from commit e1342a3

git-subtree-dir: _vendor/src/github.com/prometheus/client_golang
git-subtree-split: e1342a3d39fe887311c4b4d5ccd6e02c519a1cbd
Merge commit 'cca9d674afd7581ff9625cbed15a23b4429aac07' as '_vendor/src/github.com/prometheus/client_golang'