Next version of Civilization The Board Game

Introduction
I deployed next 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 container is brought back to life.

New features

• spend trade for production and undo spend
• scout can send production to the city and undo sending
• buying units

Spend trade for production

Just specify the number of production you want to get and the trade is reduced accordingly. So you can do shopping as you wish.The player can also undo the last spending unless it is used.
Send production from square to the city

Click the city and choose the scout you want to send production.
The player can also undo this action unless production is spent.

Click Undo button right to the grayed "Send Production" button.
Buying units

The player can buy units although the battle is not implemented yet. The unit panel shows only the number of units of a particular type. After clicking the panel, the detailed list of units including their strength is revealed. Of course, this option is not available for opposite player. Also, in the market panel, any player can see the detailed list of killed units but not the units still waiting to be taken.
Next steps

• Resource harvesting including friendly villages
• Battle