Update module github.com/spf13/cobra to v1.2.1 (#14)

* Update module github.com/spf13/cobra to v1.2.1

* go mod tidy

Co-authored-by: Renovate Bot <bot@renovateapp.com>
Co-authored-by: kouki <kouworld0123@gmail.com>

go.mod

@@ -5,8 +5,8 @@ go 1.14
 require (
 	github.com/kr/text v0.2.0 // indirect
 	github.com/mitchellh/go-homedir v1.1.0
-	github.com/spf13/cobra v1.1.3
-	github.com/spf13/viper v1.8.0
+	github.com/spf13/cobra v1.2.1
+	github.com/spf13/viper v1.8.1
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect