add lego libs pre-emptively (#357)

build/noop/forceVendor.go

@@ -0,0 +1,11 @@
+package main
+
+// this package only exists to force vendor a few packages that we will add in future prs.
+// adding them here lets us do 'govendor add +e' to add the packages to vendor and keep them
+// in the vendor directory, even if no other code references it.
+
+import (
+	_ "github.com/xenolf/lego/acmev2"
+)
+
+func main() {}