fix jsdoc

lib/networks.js

@@ -2,10 +2,10 @@
 var _ = require('lodash');
 
 /**
- * @constructor
  * A network is merely a map containing values that correspond to version
  * numbers for each bitcoin network. Currently only supporting "livenet"
  * (a.k.a. "mainnet") and "testnet".
+ * @constructor
  */
 function Network() {}