chore(deps): bump github.com/sirupsen/logrus from 1.7.0 to 1.8.1 (#13)

Bumps [github.com/sirupsen/logrus](https://github.com/sirupsen/logrus) from 1.7.0 to 1.8.1.
- [Release notes](https://github.com/sirupsen/logrus/releases)
- [Changelog](https://github.com/sirupsen/logrus/blob/master/CHANGELOG.md)
- [Commits](sirupsen/logrus@v1.7.0...v1.8.1)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/prometheus/common v0.14.0
-	github.com/sirupsen/logrus v1.7.0
+	github.com/sirupsen/logrus v1.8.1
 	github.com/stretchr/testify v1.7.0
 	gopkg.in/alecthomas/kingpin.v2 v2.2.6
 )

go.sum

@@ -259,8 +259,8 @@ github.com/sirupsen/logrus v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
 github.com/sirupsen/logrus v1.6.0 h1:UBcNElsrwanuuMsnGSlYmtmgbb23qDR5dG+6X6Oo89I=
 github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
-github.com/sirupsen/logrus v1.7.0 h1:ShrD1U9pZB12TX0cVy0DtePoCH97K8EtX+mg7ZARUtM=
-github.com/sirupsen/logrus v1.7.0/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=
+github.com/sirupsen/logrus v1.8.1 h1:dJKuHgqk1NNQlqoA6BTlM1Wf9DOH3NBjQyu0h9+AZZE=
+github.com/sirupsen/logrus v1.8.1/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
 github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
 github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=