Upgrade dependencies
Changes
=> Bump github.com/spf13/viper from 1.6.2 to 1.7.0 (#34)
=> Bump github.com/spf13/cobra from 0.0.6 to 0.0.7 (#32)
=> Bump github.com/spf13/cobra from 0.0.5 to 0.0.6 (#31)
=> Bump github.com/stretchr/testify from 1.5.0 to 1.5.1 (#30)
=> Bump github.com/stretchr/testify from 1.4.0 to 1.5.0 (#29)