Merge pull request #173 from tjade273/master

Implement rpc_modules for `geth attach` compatibility.

Author: tcoulter

lib/subproviders/geth_api_double.js

@@ -244,6 +244,11 @@ GethApiDouble.prototype.net_version = function(callback) {
   callback(null, this.state.net_version + "");
 };
 
+GethApiDouble.prototype.rpc_modules = function(callback) {
+  // returns the availible api modules and versions
+  callback(null, {"eth":"1.0","net":"1.0","rpc":"1.0","web3":"1.0","evm":"1.0"});
+};
+
 /* Functions for testing purposes only. */
 
 GethApiDouble.prototype.evm_snapshot = function(callback) {