Panning then zooming gives incorrect tile offset

[paulnebel]

I'm using leaflet.markerCluster with mapbox-gl-leaflet. If I click on a cluster without panning the map zooms to that cluster and is rendered correctly. If, however, I pan first then click on a cluster the map is rendered with an offset which results in a grey area:

I have fixed this by calling this._update() as the last operation in the _zoomEnd function definition.

[jgravois]

resolved via #95