title: ConstraintLayout margins not working
body: <p>Using the xml below the <code>marginTop</code> is getting ignored if the view's visibility that I'm constrained to is gone.</p>
  
  <p>This happens with the latest layout lib version at this time <code>com.android.support.constraint:constraint-layout:1.0.0-beta4</code></p>
  
  <p>Example:</p>
  
  <p><code>tvMessage</code> and <code>ivCommentImage</code> are <code>visible</code> - the 16dp top margin on <code>llLeftActions</code> and <code>llRightActions</code> is working fine. If the <code>ivCommentImage</code> is <code>gone</code> the margin is ignored.</p>
  
  <pre><code>&lt;android.support.v7.widget.CardView
      android:layout_width="match_parent"
      android:layout_height="wrap_content"&gt;
  
  &lt;android.support.constraint.ConstraintLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:paddingBottom="16dp"&gt;
  
  &lt;!-- some more views here --&gt;
  
      &lt;TextView
          android:id="@+id/tvMessage"
          style="@style/SocialFeed.Description"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_marginEnd="16dp"
          android:layout_marginLeft="16dp"
          android:layout_marginRight="16dp"
          android:layout_marginStart="16dp"
          android:layout_marginTop="16dp"
          app:layout_constraintHorizontal_bias="0.0"
          app:layout_constraintLeft_toLeftOf="parent"
          app:layout_constraintRight_toRightOf="parent"
          app:layout_constraintTop_toBottomOf="@+id/ivProfile"
          app:layout_goneMarginTop="0dp"
          tools:text="@string/lorem_ipsum_140chars"/&gt;
  
      &lt;android.support.v7.widget.AppCompatImageView
          android:id="@+id/ivCommentImage"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_marginTop="16dp"
          android:adjustViewBounds="true"
          app:layout_constraintLeft_toLeftOf="parent"
          app:layout_constraintRight_toRightOf="parent"
          app:layout_constraintTop_toBottomOf="@+id/tvMessage"
          app:layout_goneMarginTop="0dp"
          /&gt;
  
      &lt;android.support.constraint.Guideline
          android:id="@+id/gCenter"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:orientation="vertical"
          app:layout_constraintGuide_percent="0.5"/&gt;
  
      &lt;LinearLayout
          android:id="@+id/llLeftActions"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_marginTop="16dp"
          android:gravity="center_vertical|left"
          android:orientation="horizontal"
          app:layout_constraintLeft_toLeftOf="@+id/tvMessage"
          app:layout_constraintRight_toLeftOf="@+id/gCenter"
          app:layout_constraintTop_toBottomOf="@+id/ivCommentImage"
          app:layout_goneMarginTop="0dp"
          /&gt;
  
      &lt;LinearLayout
          android:id="@+id/llRightActions"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_marginTop="16dp"
          android:gravity="center_vertical|right"
          android:orientation="horizontal"
          app:layout_constraintLeft_toLeftOf="@+id/gCenter"
          app:layout_constraintRight_toRightOf="@+id/tvMessage"
          app:layout_constraintTop_toBottomOf="@+id/ivCommentImage"
          app:layout_goneMarginTop="0dp"/&gt;
  
  
  &lt;/android.support.constraint.ConstraintLayout&gt;
  
  &lt;/android.support.v7.widget.CardView&gt;
  </code></pre>