Merge branch 'metrics-measure-block' into 'master'

Support for measuring Ruby blocks using GitLab performance monitoring

This adds support for measuring timings of arbitrary Ruby blocks.

Fixes #14710 

See merge request !3515
25 jobs for master
Status Job ID Name Coverage
  Test
passed #1012945
brakeman

00:02:54

passed #1012948
bundler:audit

00:08:56

passed #1012947
flay

00:01:47

passed #1012946
flog

00:10:25

passed #1012943
rubocop

00:04:49

passed #1012944
scss-lint

00:08:18

passed #1012934
spec:api

00:23:06

passed #1012950
spec:api:ruby22

00:25:49

passed #1012933
spec:feature

00:26:22

passed #1012949
spec:feature:ruby22

00:38:09

passed #1012936
spec:lib

00:19:13

passed #1012952
spec:lib:ruby22

00:26:43

passed #1012935
spec:models

00:21:14

passed #1012951
spec:models:ruby22

00:34:02

passed #1012938
spec:other

00:20:45

passed #1012954
spec:other:ruby22

00:25:35

passed #1012937
spec:services

00:23:19

passed #1012953
spec:services:ruby22

00:31:31

passed #1012941
spinach:other

00:36:51

passed #1012957
spinach:other:ruby22

00:23:28

passed #1012939
spinach:project:half

00:28:00

passed #1012955
spinach:project:half:ruby22

00:30:03

passed #1012940
spinach:project:rest

00:19:30

passed #1012956
spinach:project:rest:ruby22

00:35:34

passed #1012942
teaspoon

00:02:34