Allow access to getrawmempool verbose mode

This will give access to the ancestorsize and ancestorfees for txes in the mempool.

I am using this to implement CPFP needed fees api for insight-api

Author: dabura667

lib/index.js

@@ -175,7 +175,7 @@ RpcClient.callspec = {
   getMiningInfo: '',
   getNewAddress: '',
   getPeerInfo: '',
-  getRawMemPool: '',
+  getRawMemPool: 'bool',
   getRawTransaction: 'str int',
   getReceivedByAccount: 'str int',
   getReceivedByAddress: 'str int',