Merge pull request #37 from huandzh/patch-1

hackage新的安全机制需要增加同步若干json文件

hackage.sh

@@ -51,6 +51,14 @@ function hackage_mirror() {
 	rm index.tar.gz || true
 	wget "${base_url}/01-index.tar.gz" -O index.tar.gz &> /dev/null
 
+	# https://hackage.haskell.org/api#security
+	echo "Dowloading security features..."
+	jsons=("timestamp.json" "snapshot.json" "root.json" "mirrors.json")
+	for name in "${jsons[@]}"
+	do
+    		wget "${base_url}/${name}" -O ${name}
+	done
+	
 	echo "building local package list"
 	local tmp
 	tmp=(package/*)