build(deps): Bump github.com/prometheus/common

Bumps [github.com/prometheus/common](https://github.com/prometheus/common) from 0.17.0 to 0.19.0.
- [Release notes](https://github.com/prometheus/common/releases)
- [Commits](prometheus/common@v0.17.0...v0.19.0)

Signed-off-by: dependabot[bot] <support@github.com>

receiver/simpleprometheusreceiver/go.mod

@@ -3,7 +3,7 @@ module github.com/open-telemetry/opentelemetry-collector-contrib/receiver/simple
 go 1.14
 
 require (
-	github.com/prometheus/common v0.17.0
+	github.com/prometheus/common v0.19.0
 	github.com/prometheus/prometheus v1.8.2-0.20201105135750-00f16d1ac3a4
 	github.com/stretchr/testify v1.7.0
 	go.opentelemetry.io/collector v0.21.0

receiver/simpleprometheusreceiver/go.sum

@@ -845,6 +845,8 @@ github.com/prometheus/common v0.14.0/go.mod h1:U+gB1OBLb1lF3O42bTCL+FK18tX9Oar16
 github.com/prometheus/common v0.15.0/go.mod h1:U+gB1OBLb1lF3O42bTCL+FK18tX9Oar16Clt/msog/s=
 github.com/prometheus/common v0.17.0 h1:kDIZLI74SS+3tedSvEkykgBkD7txMxaJAPj8DtJUKYA=
 github.com/prometheus/common v0.17.0/go.mod h1:U+gB1OBLb1lF3O42bTCL+FK18tX9Oar16Clt/msog/s=
+github.com/prometheus/common v0.19.0 h1:Itb4+NjG9wRdkAWgVucbM/adyIXxEhbw0866e0uZE6A=
+github.com/prometheus/common v0.19.0/go.mod h1:U+gB1OBLb1lF3O42bTCL+FK18tX9Oar16Clt/msog/s=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/prometheus/procfs v0.0.0-20181204211112-1dc9a6cbc91a/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/prometheus/procfs v0.0.0-20190117184657-bf6a532e95b1/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=