build: bump github.com/slack-go/slack from 0.11.4 to 0.12.2

Bumps [github.com/slack-go/slack](https://github.com/slack-go/slack) from 0.11.4 to 0.12.2.
- [Release notes](https://github.com/slack-go/slack/releases)
- [Changelog](https://github.com/slack-go/slack/blob/master/CHANGELOG.md)
- [Commits](slack-go/slack@v0.11.4...v0.12.2)

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

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

go.mod

@@ -38,7 +38,7 @@ require (
 	github.com/rikatz/kubepug v1.4.0
 	github.com/segmentio/analytics-go/v3 v3.2.1
 	github.com/skratchdot/open-golang v0.0.0-20200116055534-eef842397966
-	github.com/slack-go/slack v0.11.4
+	github.com/slack-go/slack v0.12.2
 	github.com/spf13/cobra v1.6.1
 	github.com/stretchr/testify v1.8.2
 	github.com/valyala/fasthttp v1.44.0

go.sum

@@ -556,8 +556,8 @@ github.com/sirupsen/logrus v1.9.0 h1:trlNQbNUG3OdDrDil03MCb1H2o9nJ1x4/5LYw7byDE0
 github.com/sirupsen/logrus v1.9.0/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/skratchdot/open-golang v0.0.0-20200116055534-eef842397966 h1:JIAuq3EEf9cgbU6AtGPK4CTG3Zf6CKMNqf0MHTggAUA=
 github.com/skratchdot/open-golang v0.0.0-20200116055534-eef842397966/go.mod h1:sUM3LWHvSMaG192sy56D9F7CNvL7jUJVXoqM1QKLnog=
-github.com/slack-go/slack v0.11.4 h1:ojSa7KlPm3PqY2AomX4VTxEsK5eci5JaxCjlzGV5zoM=
-github.com/slack-go/slack v0.11.4/go.mod h1:hlGi5oXA+Gt+yWTPP0plCdRKmjsDxecdHxYQdlMQKOw=
+github.com/slack-go/slack v0.12.2 h1:x3OppyMyGIbbiyFhsBmpf9pwkUzMhthJMRNmNlA4LaQ=
+github.com/slack-go/slack v0.12.2/go.mod h1:hlGi5oXA+Gt+yWTPP0plCdRKmjsDxecdHxYQdlMQKOw=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spf13/cobra v1.6.1 h1:o94oiPyS4KD1mPy2fmcYYHHfCxLqYjJOhGsCHFZtEzA=
 github.com/spf13/cobra v1.6.1/go.mod h1:IOw/AERYS7UzyrGinqmz6HLUo219MORXGxhbaJUqzrY=