Add tests

go.mod

@@ -6,12 +6,13 @@ require (
 	cloud.google.com/go/pubsub v1.0.1
 	github.com/elastic/go-concert v0.0.4
 	github.com/google/gopacket v1.1.19
+	github.com/ory/dockertest/v3 v3.6.3
 	github.com/spf13/cobra v1.1.1
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.4.0
 	go.uber.org/multierr v1.1.0
 	go.uber.org/zap v1.10.0
-	golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0
+	golang.org/x/sys v0.0.0-20200831180312-196b9ba8737a
 	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4
 	google.golang.org/api v0.13.0
 )