No more path rewriting

Path rewriting causes too many problems when vendoring
vendored code. When CNI code is vendored into rkt,
godep has problems code already vendored by CNI.

plugins/ipam/dhcp/options.go

@@ -20,8 +20,8 @@ import (
 	"net"
 	"time"
 
-	"github.com/appc/cni/Godeps/_workspace/src/github.com/d2g/dhcp4"
 	"github.com/appc/cni/pkg/plugin"
+	"github.com/d2g/dhcp4"
 )
 
 func parseRouter(opts dhcp4.Options) net.IP {