Fix download forgery

app/rediscache.py

@@ -0,0 +1,13 @@
+from . import r
+
+# This file acts as a facade between the releases code and redis,
+# and also means that the releases code avoids knowing about `app`
+
+def make_download_key(ip, package):
+	return ("{}/{}/{}").format(ip, package.author.username, package.name)
+
+def set_key(key, v):
+	r.set(key, v)
+
+def has_key(key):
+	return r.exists(key)