chore: update to go1.13

.travis.yml

@@ -14,7 +14,7 @@ cache:
 matrix:
   fast_finish: true
   include:
-    - go: 1.12.x
+    - go: 1.13.x
       env: STABLE=true
     - go: 1.x
     - go: tip

go.mod

@@ -7,11 +7,9 @@ require (
 	github.com/containous/traefik/v2 v2.0.0-rc1
 	github.com/fsnotify/fsnotify v1.4.8-0.20190312181446-1485a34d5d57
 	github.com/go-acme/lego/v3 v3.0.2
-	github.com/hashicorp/consul/api v1.2.0 // indirect
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/viper v1.4.0
-	google.golang.org/grpc v1.23.0 // indirect
 )
 
 // related to valkeyrie