fixed error handling, added list command, switched to koanf

upd/upd.hcl

@@ -1,6 +1,16 @@
 # -*-ruby-*-
 listen = ":8080"
-apikeys = [
-  "0fddbff5d8010f81cd28a7d77f3e38981b13d6164c2fd6e1c3f60a4287630c37",
-  "970b391f22f515d96b3e9b86a2c62c627968828e47b356994d2e583188b4190a"
+bodylimit = 10000
+
+apicontext = [
+  {
+    context = "default"
+    key = "0fddbff5d8010f81cd28a7d77f3e38981b13d6164c2fd6e1c3f60a4287630c37",
+  },
+  {
+    context = "foo",
+    key = "970b391f22f515d96b3e9b86a2c62c627968828e47b356994d2e583188b4190a"
+  }
 ]
+
+