Initialize update script

My initial thought for this: create a simple redis db for storing key
value pairs of instance -> list of live instances for each privacy front
end (libreddit, bibliogram, etc). A script executed on a certain
schedule would (in the background) check each instance to make sure it
isn't down or unreasonably slow. If the instance is available, add it to
a list of available instances in the db.

When a user navigates to the revolver url (something like
<url>/<service>/<...>), the app would pick a random value from the list
returned by redis.get('<service>') and forward the user to that
instance.

As a side note, this could instead load the instances json from a remote
source (like github or something) so that changes to instances don't
need to involve a redeploy of the entire app.

update.exs

@@ -0,0 +1,21 @@
+defmodule Instance do
+  defstruct [
+    instance_type: nil,
+    instance_list: []
+  ]
+end
+
+defmodule Instances do
+  def update(filename) do
+    {:ok, file} = File.read(filename)
+    {:ok, json} = Poison.decode(file, as: [%Instance{}])
+    for x <- json do
+      IO.puts(x.instance_type)
+      for y <- x.instance_list do
+        IO.puts(" - " <> y)
+      end
+    end
+  end
+end
+
+Instances.update("instances.json")