mod: bump dependencies

go.mod

@@ -4,19 +4,18 @@ go 1.12
 
 require (
 	github.com/libp2p/go-reuseport v0.0.1
-	github.com/magiconair/properties v1.8.1 // indirect
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/pelletier/go-toml v1.4.0 // indirect
 	github.com/pkg/errors v0.8.1
-	github.com/prometheus/client_golang v1.1.0
+	github.com/prometheus/client_golang v1.3.0
 	github.com/spf13/afero v1.2.2 // indirect
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/jwalterweatherman v1.1.0 // indirect
-	github.com/spf13/pflag v1.0.3
-	github.com/spf13/viper v1.4.0
-	go.uber.org/zap v1.10.0
+	github.com/spf13/pflag v1.0.5
+	github.com/spf13/viper v1.6.1
+	go.uber.org/zap v1.13.0
 	golang.org/x/text v0.3.2 // indirect
-	gopkg.in/yaml.v2 v2.2.3
+	gopkg.in/yaml.v2 v2.2.7
 	gortc.io/ice v0.7.0
 	gortc.io/stun v1.22.0
 	gortc.io/turn v0.11.2