Update travis to run make build

Ensure all packages can be built, even those not yet imported by binaries.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

fs/fstest/file.go

@@ -5,8 +5,6 @@ import (
 	"os"
 	"path/filepath"
 	"time"
-
-	"github.com/containerd/continuity/sysx"
 )
 
 // Applier applies single file changes
@@ -96,12 +94,6 @@ func Link(oldname, newname string) Applier {
 	})
 }
 
-func SetXAttr(name, key, value string) Applier {
-	return applyFn(func(root string) error {
-		return sysx.LSetxattr(name, key, []byte(value), 0)
-	})
-}
-
 // TODO: Make platform specific, windows applier is always no-op
 //func Mknod(name string, mode int32, dev int) Applier {
 //	return func(root string) error {

fs/fstest/file_unix.go

@@ -0,0 +1,11 @@
+// +build !windows
+
+package fstest
+
+import "github.com/containerd/continuity/sysx"
+
+func SetXAttr(name, key, value string) Applier {
+	return applyFn(func(root string) error {
+		return sysx.LSetxattr(name, key, []byte(value), 0)
+	})
+}