Add new image test

Author: hannahker

test/image/mocks/zz-container-colorbar-vertical-w-margin.json

@@ -0,0 +1,48 @@
+{
+    "data": [
+        {
+            "colorbar": {
+                "orientation": "v",
+                "xref": "container",
+                "x": 1,
+                "thickness": 10,
+                "ticks": "outside",
+                "bgcolor": "rgba(255,255,0,0.5)",
+                "borderwidth": 4,
+                "bordercolor": "gray",
+                "title": {
+                  "side": "top",
+                  "text": "Colorbar<br>title",
+                  "font": {
+                    "size": 16
+                  }
+                }
+            },
+            "z": [
+               [
+                  1,
+                  3,
+                  5
+               ],
+               [
+                  4,
+                  7,
+                  10
+               ],
+               [
+                  7,
+                  11,
+                  14
+               ]
+            ],
+            "type": "heatmap"
+        }
+    ],
+    "layout": {
+        "margin": {"l": 0, "r": 148, "t": 0, "b": 0},
+        "height": 300,
+        "width": 400,
+        "yaxis": {"automargin": true, "side": "right", "title": {"text": "Y-axis title"}},
+        "title": {"text": "Colorbar with `xref='container'` | vertical | margin", "automargin": true}
+    }
+}