update build format

build.json

@@ -1,10 +1,18 @@
 {
-  "CritterCrossing": {
-          "dir": "app",
-          "artifacts": ["build/"]
-  },
-  "CritterScraper": {
-          "dir": "scraper",
-          "artifacts": ["build/"]
-  }
-}
+  "subprojects": [
+    {
+      "name": "CritterCrossing",
+      "dir": "app",
+      "artifacts": [
+        "build/"
+      ]
+    },
+    {
+      "name": "CritterScraper",
+      "dir": "scraper",
+      "artifacts": [
+        "build/"
+      ]
+    }
+  ]
+}