add mapbox using OSM map raster style mock

Author: etpinard

Diff for: test/image/baselines/mapbox_osm-style.png

@@ -0,0 +1,36 @@
+{
+  "data": [
+    {
+      "type": "scattermapbox",
+      "lon": [ 10, 20 ],
+      "lat": [ 20, 10 ]
+    }
+  ],
+  "layout": {
+    "mapbox": {
+      "style": {
+        "id": "osm",
+        "version": 8,
+        "sources": {
+          "simple-tiles": {
+            "type": "raster",
+            "tiles": [
+              "https://a.tile.openstreetmap.org/{z}/{x}/{y}.png",
+              "https://b.tile.openstreetmap.org/{z}/{x}/{y}.png"
+            ],
+            "tileSize": 256
+          }
+        },
+        "layers": [
+          {
+            "id": "simple-tiles",
+            "type": "raster",
+            "source": "simple-tiles",
+            "minzoom": 0,
+            "maxzoom": 22
+          }
+        ]
+      }
+    }
+  }
+}