Update / cleanup go.mod.

Author: brocaar

go.mod

@@ -4,26 +4,15 @@ require (
 	github.com/brocaar/loraserver v0.0.0-20190422074053-c3336fb6b947
 	github.com/brocaar/lorawan v0.0.0-20190402092148-5bca41b178e9
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible
-	github.com/eclipse/paho.mqtt.golang v1.1.1
+	github.com/eclipse/paho.mqtt.golang v1.2.0
 	github.com/golang/protobuf v1.3.1
-	github.com/goreleaser/goreleaser v0.101.0
-	github.com/goreleaser/nfpm v0.9.7
+	github.com/goreleaser/goreleaser v0.106.0
 	github.com/gorilla/websocket v1.4.0
-	github.com/jacobsa/crypto v0.0.0-20190317225127-9f44e2d11115 // indirect
-	github.com/mattn/go-colorable v0.1.1 // indirect
-	github.com/mattn/go-isatty v0.0.7 // indirect
 	github.com/pkg/errors v0.8.1
 	github.com/prometheus/client_golang v0.9.2
-	github.com/prometheus/client_model v0.0.0-20190115171406-56726106282f // indirect
-	github.com/prometheus/common v0.1.0 // indirect
-	github.com/prometheus/procfs v0.0.0-20190104112138-b1a0a9a36d74 // indirect
 	github.com/sirupsen/logrus v1.4.1
 	github.com/spf13/cobra v0.0.3
-	github.com/spf13/viper v1.3.1
+	github.com/spf13/viper v1.3.2
 	github.com/stretchr/testify v1.3.0
 	golang.org/x/lint v0.0.0-20190409202823-959b441ac422
-	golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 // indirect
-	golang.org/x/sys v0.0.0-20190405154228-4b34438f7a67 // indirect
-	golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2 // indirect
-	golang.org/x/tools v0.0.0-20190409223705-96f2e7ef861b // indirect
 )