fix a format error in libraries-and-tools.md

Documentation/libraries-and-tools.md

@@ -43,7 +43,7 @@
 **Erlang libraries**
 
 - [marshall-lee/etcd.erl](https://github.com/marshall-lee/etcd.erl)
-- 
+
 **.Net Libraries**
 -[drusellers/etcetera](https://github.com/drusellers/etcetera)