correction map

web/js/leaflet-1.3.1/plugins/leaflet.markercluster-1.3.0/example/screen.css

+#map {
+	width: 800px; 
+	height: 600px; 
+	border: 1px solid #ccc;
+}
+
+#progress {
+    display: none;
+    position: absolute;
+    z-index: 1000;
+    left: 400px;
+    top: 300px;
+    width: 200px;
+    height: 20px;
+    margin-top: -20px;
+    margin-left: -100px;
+    background-color: #fff;
+    background-color: rgba(255, 255, 255, 0.7);
+    border-radius: 4px;
+    padding: 2px;
+}
+
+#progress-bar {
+    width: 0;
+    height: 100%;
+    background-color: #76A6FC;
+    border-radius: 4px;
+}

web/js/leaflet-1.3.1/plugins/leaflet.markercluster-1.3.0/spec/after.js

+// put after Leaflet files as imagePath can't be detected in a PhantomJS env
+L.Icon.Default.imagePath = "../dist/images";