fixes #2044: add -showAnnotations:animated:

include/mbgl/ios/MGLMapView.h

@@ -151,6 +151,13 @@ IB_DESIGNABLE
 *   @param animated Specify `YES` to animate the change by smoothly scrolling and zooming or `NO` to immediately display the given bounds. */
 - (void)setVisibleCoordinates:(CLLocationCoordinate2D *)coordinates count:(NSUInteger)count edgePadding:(UIEdgeInsets)insets animated:(BOOL)animated;
 
+/** Sets the visible region so that the map displays the specified annotations.
+*
+*   Calling this method updates the value in the visibleCoordinateBounds property and potentially other properties to reflect the new map region.
+*   @param annotations The annotations that you want to be visible in the map.
+*   @param animated `YES` if you want the map region change to be animated, or `NO` if you want the map to display the new region immediately without animations. */
+- (void)showAnnotations:(NS_ARRAY_OF(id <MGLAnnotation>) *)annotations animated:(BOOL)animated;
+
 /** The heading of the map (measured in degrees) relative to true north. 
 *
 *   The value `0` means that the top edge of the map view corresponds to true north. The value `90` means the top of the map is pointing due east. The value `180` means the top of the map points due south, and so on. */