Use new packngo API allowing passing in a custom http.Client

builtin/providers/packet/config.go

@@ -1,6 +1,8 @@
 package packet
 
 import (
+	"net/http"
+
 	"github.com/packethost/packngo"
 )
 
@@ -14,5 +16,5 @@ type Config struct {
 
 // Client() returns a new client for accessing packet.
 func (c *Config) Client() *packngo.Client {
-	return packngo.NewClient(consumerToken, c.AuthToken)
+	return packngo.NewClient(consumerToken, c.AuthToken, &http.Client{})
 }