Makefile fixes: (#1892)

Correctly set the path for the presubmits, fix some typos and make
the goimport target do the linting to the lint target can be removed.

Also don't make it a fatal error because gofmt changes between releases.

plugin/kubernetes/handler_ignore_emptyservice_test.go

@@ -2,9 +2,10 @@ package kubernetes
 
 import (
 	"context"
+	"testing"
+
 	"github.com/coredns/coredns/plugin/pkg/dnstest"
 	"github.com/coredns/coredns/plugin/test"
-	"testing"
 
 	"github.com/miekg/dns"
 )