Implement chapter 4 - part1

- pull photo urls from the server
- provide styles.css and list ourselves

elm.json

@@ -9,9 +9,12 @@
             "elm/browser": "1.0.2",
             "elm/core": "1.0.5",
             "elm/html": "1.0.0",
+            "elm/http": "2.0.0",
             "elm/random": "1.0.0"
         },
         "indirect": {
+            "elm/bytes": "1.0.8",
+            "elm/file": "1.0.5",
             "elm/json": "1.1.3",
             "elm/time": "1.0.0",
             "elm/url": "1.0.0",