Can't integrate Project Tango with Unity

I can't integrate Project Tango with Unity. I'm using Android Studio 1.3 on Windows 8.1 and have verified that my Project Tango Development kit is properly supporting USB debugging as I have successfully gotten the JavaQuickStart app to compile and execute on my Project Tango device via the USB connection. The first time I tried to build a project for Android in Unity I was not asked to locate the folder where I installed the SDK so I manually went to Edit (not Unity as in the documentation) >Preferences > External Tools to enter my Andorid SDK Location. I used the SDK location found in my SDK location at AndroidStudio>Configuration>SDK Manager and used the SDK Path: C:.....\Android\sdk .

Next I was able to navigate to Player Settings and set the Minimum API(not APK per documentation) Level to 17.

I also successfully set up a new project in Unity, however, when I tried to import the Tango SDK . unitypackage file I got an error "Failed to import package with error: Couldn't decompress package". The Unity package file is TangoSDK_Xiaotong_Unity.

I would appreciate any help I can get. Thanks in advance. SteveD2015