build(deps): bump github.com/spf13/viper from 1.7.1 to 1.8.0

Bumps [github.com/spf13/viper](https://github.com/spf13/viper) from 1.7.1 to 1.8.0.
- [Release notes](https://github.com/spf13/viper/releases)
- [Commits](https://github.com/spf13/viper/compare/v1.7.1...v1.8.0)

---
updated-dependencies:
- dependency-name: github.com/spf13/viper
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

go.mod

@@ -22,18 +22,16 @@ require (
 	github.com/opentracing/opentracing-go v1.2.0
 	github.com/rs/zerolog v1.23.0
 	github.com/spf13/cobra v1.1.3
-	github.com/spf13/viper v1.7.1
+	github.com/spf13/viper v1.8.0
 	github.com/stretchr/testify v1.7.0
 	github.com/tonistiigi/fsutil v0.0.0-20201103201449-0834f99b7b85
 	github.com/tonistiigi/units v0.0.0-20180711220420-6950e57a87ea
 	github.com/uber/jaeger-client-go v2.29.1+incompatible
 	github.com/uber/jaeger-lib v2.4.1+incompatible // indirect
 	go.mozilla.org/sops/v3 v3.7.1
-	go.uber.org/atomic v1.7.0 // indirect
 	golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c // indirect
-	golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9
+	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
 	golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1
-	golang.org/x/text v0.3.4 // indirect
 	golang.org/x/time v0.0.0-20200416051211-89c76fbcd5d1
 	google.golang.org/grpc v1.38.0
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b