add geth_extra_opts options, can be used to set --vmdebug to geth

README.md

@@ -258,6 +258,7 @@ The environment is a specific blockchain configuration that can be managed at co
     chains: chains_staging.json
     network_id: 0
     console: true
+    geth_extra_opts: --vmdebug
     account:
       init: false
       address: 0x123

lib/blockchain.js

@@ -16,6 +16,10 @@ Blockchain.prototype.generate_basic_command = function() {
     cmd += "--logfile=\"" + config.datadir + ".log\" ";
   }
 
+  if (config.geth_extra_opts) {
+    cmd += config.geth_extra_opts + " ";
+  }
+
   cmd += "--port " + config.port + " ";
   cmd += "--rpc ";
   cmd += "--rpcport " + config.rpcPort + " ";

lib/config/blockchain.js

@@ -48,7 +48,8 @@ BlockchainConfig.prototype.config = function(env) {
     console_toggle: config.console || false,
     mine_when_needed: config.mine_when_needed || false,
     whisper: config.whisper || false,
-    account: config.account
+    account: config.account,
+    geth_extra_opts: config.geth_extra_opts
   }
 
   return config;