Bump github.com/stretchr/testify from 1.8.4 to 1.9.0

Bumps [github.com/stretchr/testify](https://github.com/stretchr/testify) from 1.8.4 to 1.9.0.
- [Release notes](https://github.com/stretchr/testify/releases)
- [Commits](stretchr/testify@v1.8.4...v1.9.0)

---
updated-dependencies:
- dependency-name: github.com/stretchr/testify
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod

@@ -15,7 +15,7 @@ require (
 	github.com/prometheus/exporter-toolkit v0.11.0
 	github.com/prometheus/prometheus v1.8.2-0.20210119214810-e4487274853c
 	github.com/prometheus/statsd_exporter v0.26.0
-	github.com/stretchr/testify v1.8.4
+	github.com/stretchr/testify v1.9.0
 )
 
 require (

go.sum

@@ -705,8 +705,8 @@ github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81P
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/tidwall/pretty v1.0.0/go.mod h1:XNkn88O1ChpSDQmQeStsy+sBenx6DDtFZJxhVysOjyk=
 github.com/tinylib/msgp v1.0.2/go.mod h1:+d+yLhGm8mzTaHzB+wgMYrodPfmZrzkirds8fDWklFE=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20170815181823-89b8d40f7ca8/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=