message: Fix for issue
  Issue - Why does my `overlayTop` tab bar appear at bottom
diff: @@ -292,14 +292,15 @@ const ScrollableTabView = createReactClass({
  left: 0,
  right: 0,
  [this.props.tabBarPosition === "overlayTop" ? "top" : "bottom"]: 0,
  + backgroundColor: "rgba(255, 255, 255, 0.7)",
  };
  }
  return (
  <View style={[styles.container, this.props.style]} onLayout={this._handleLayout}>
  - {this.props.tabBarPosition === "top" && this.renderTabBar(tabBarProps)}
  + {(this.props.tabBarPosition === "top" || this.props.tabBarPosition==="overlayTop")&& this.renderTabBar(tabBarProps)}
  {this.renderScrollableContent()}
  - {(this.props.tabBarPosition === "bottom" || overlayTabs) && this.renderTabBar(tabBarProps)}
  + {(this.props.tabBarPosition === "bottom" || this.props.tabBarPosition==="overlayBottom") && this.renderTabBar(tabBarProps)}
  </View>
  );
  },
  