title: ConstraintLayout 1.1.0 different from 1.0.2, is it a bug?
body: <p>If I use 1.0.2, the 3 images' width is average, and the height of them is computed by the radio which I set. If I use 1.1.0, the height of them is <code>0dp</code> and I can't see nothing, unless I set<br>
  <code>android:layout_height="match_parent"</code><br>
  in the root <code>ConstraintLayout</code>.</p>
  
  <p>Is it a bug? Here is my code:</p>
  
  <pre><code>&lt;android.support.constraint.ConstraintLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"&gt;
  
      &lt;ImageView
          android:id="@+id/iv0"
          android:layout_width="0dp"
          android:layout_height="0dp"
          android:background="#FF0000"
          app:layout_constraintLeft_toLeftOf="parent"
          app:layout_constraintRight_toLeftOf="@+id/iv1"
          app:layout_constraintDimensionRatio="2:1"/&gt;
  
      &lt;ImageView
          android:id="@+id/iv1"
          android:layout_width="0dp"
          android:layout_height="0dp"
          android:background="#00FF00"
          app:layout_constraintDimensionRatio="2:1"
          app:layout_constraintLeft_toRightOf="@id/iv0"
          app:layout_constraintRight_toLeftOf="@+id/iv2"/&gt;
  
      &lt;ImageView
          android:id="@+id/iv2"
          android:layout_width="0dp"
          android:layout_height="0dp"
          android:background="#0000FF"
          app:layout_constraintDimensionRatio="2:1"
          app:layout_constraintRight_toRightOf="parent"
          app:layout_constraintLeft_toRightOf="@id/iv1"/&gt;
  
  &lt;/android.support.constraint.ConstraintLayout&gt;
  </code></pre>