title: Error using databinding in android
body: <p>I am trying to test data binding as given in the guide <a href="https://developer.android.com/tools/data-binding/guide.html" rel="noreferrer">here</a>. 
  I have included this in my build.gradle file (of module app) :</p>
  
  <pre><code>compileSdkVersion 'android-MNC'
  buildToolsVersion '23.0.0 rc2'
  </code></pre>
  
  <p>In the project build.gradle file, I have included this in my dependencies :</p>
  
  <pre><code>classpath "com.android.tools.build:gradle:1.3.0-beta2"
  classpath "com.android.databinding:dataBinder:1.0-rc0"
  </code></pre>
  
  <p>The layout file is exactly the same as the one given in the guide.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;layout xmlns:android="http://schemas.android.com/apk/res/android"&gt;
  &lt;data&gt;
     &lt;variable name="user" type="com.example.User"/&gt;
  &lt;/data&gt;
  &lt;LinearLayout
     android:orientation="vertical"
     android:layout_width="match_parent"
     android:layout_height="match_parent"&gt;
     &lt;TextView android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="@{user.firstName}"/&gt;
     &lt;TextView android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="@{user.lastName}"/&gt;
  &lt;/LinearLayout&gt;
  &lt;/layout&gt;
  </code></pre>
  
  <p>Initially it gave an error <code>Element layout does not have the required attribute layout_width and layout_height</code>. </p>
  
  <p>I tried to fix it by assigning match_parent to both. Then I got the error
  <code>Error parsing XML: duplicate attribute</code> on the lines where i assigned <code>layout_height</code> and <code>layout_width</code> to the linear layout.</p>
  
  <p>Again I tried to fix this by removing these attributes. Now every time I try to compile, I see this- <code>error: package my.package.name.databinding</code> does not exist.</p>
  
  <p>The code completion is working perfectly in my Fragment where I am trying to use this layout.</p>
  
  <p>So what did I miss ?</p>