Civilization The Board Game, next version

Introduction
I deployed a new version of my computer implementation of  Civilization The Board Game. The implementation consists of three parts:

• Civilization Engine 
• Civilization Web Interface
• Demo. Demo version is deployed to Heroku, free quota. Please wait several minutes unless the dyno is brought back to life.

New features

• "Writing" technology implemented, the player can cancel city action of his opponent
• "HangingGarden" wonder implemented

"Writing" technology
If you have "Writing" technology and was able to recruit the Spy then you can tell "every dog has its day".

The execution of the player city action is postponed unless his opponent decides to cancel it or be merciful (this time). You have to take a decision quickly otherwise the opponent may know that you have something up your sleeve.

The opponent wants to build a Libary and now you have to take a decision: turn thumb down and cancel it or turn thumb up.
If you decide to slap him in the face, do not be astonished that your Spy is uncovered and gone.

The HangingGarden wonder

Now at the beginning of the turn, you can purchase your figure for free provided is available.

Next step
Implement a journal, display messages related to the game. For instance, if "Writing" technology was used the opponent should be informed what had happened.