move code runner to core modules

lib/contracts/blockchain.js

@@ -5,6 +5,7 @@ const utils = require('../utils/utils');
 
 const WEB3_READY = 'web3Ready';
 
+// TODO: consider another name, this is the blockchain connector
 class Blockchain {
   constructor(options) {
     const self = this;

lib/core/engine.js

@@ -142,7 +142,7 @@ class Engine {
   }
 
   codeRunnerService(_options) {
-    const CodeRunner = require('../coderunner/codeRunner.js');
+    const CodeRunner = require('./modules/coderunner/codeRunner.js');
     this.codeRunner = new CodeRunner({
       plugins: this.plugins,
       events: this.events,