Preserve File Permissions from Tar Files

- Ensure that file permissions are kept when untarring Docker SDK
diff --git a/tests/src/system/basic/WskSdkTests.scala b/tests/src/system/basic/WskSdkTests.scala
index 90f5a56..0c79349 100644
--- a/tests/src/system/basic/WskSdkTests.scala
+++ b/tests/src/system/basic/WskSdkTests.scala
@@ -60,6 +60,9 @@
             // confirm that the image is correct
             lines.get(1) shouldBe "FROM openwhisk/dockerskeleton"
 
+            val buildAndPushFile = new File(sdk, "buildAndPush.sh")
+            buildAndPushFile.canExecute() should be(true)
+
             // confirm there is no other divergence from the base dockerfile
             val originalDockerfile = WhiskProperties.getFileRelativeToWhiskHome("sdk/docker/Dockerfile")
             val originalLines = FileUtils.readLines(originalDockerfile)