fix #188: display response image in html report

tests/httpbin/load_image.yml

@@ -0,0 +1,37 @@
+- config:
+    name: load images
+    request:
+        base_url: https://httpbin.org
+
+- test:
+    name: get png image
+    request:
+        url: /image/png
+        method: GET
+    validators:
+        - eq: ["status_code", 200]
+
+- test:
+    name: get jpeg image
+    request:
+        url: /image/jpeg
+        method: GET
+    validators:
+        - eq: ["status_code", 200]
+
+- test:
+    name: get webp image
+    request:
+        url: /image/webp
+        method: GET
+    validators:
+        - eq: ["status_code", 200]
+
+- test:
+    name: get svg image
+    request:
+        url: /image/svg
+        method: GET
+    validators:
+        - eq: ["status_code", 200]
+