Removed some console

Fixed issue 60

src/clientOperations/volatileSubscriptionOperation.js

@@ -46,7 +46,7 @@ VolatileSubscriptionOperation.prototype._inspectPackage = function(pkg) {
     }
     return null;
   } catch(e) {
-    console.log(e.stack);
+    this._log.warn(e.stack);
     return null;
   }
 };
@@ -55,4 +55,4 @@ VolatileSubscriptionOperation.prototype._createSubscriptionObject = function(las
   return new VolatileEventStoreSubscription(this, this._streamId, lastCommitPosition, lastEventNumber);
 };
 
-module.exports = VolatileSubscriptionOperation;
+module.exports = VolatileSubscriptionOperation;