Fixing the vertical position of a card image.

The diff is pretty self-explanatory.  I tested some different positions and it appears that adjusting the card image down by 12 pixels produces the closest result to the actual in-game images.

Here is what is generated by my fix.
![infantry_00](https://f.cloud.github.com/assets/2695225/1061729/ac427878-11fc-11e3-92cb-1c406b3e83a2.png)

Here is the version currently on http://purei.github.io/tyrant-card-builder
![infantry_01](https://f.cloud.github.com/assets/2695225/1061731/e1c279f8-11fc-11e3-88f5-a7daf7e29595.png)

Here is the in game screenshot I took.
![infantry_02](https://f.cloud.github.com/assets/2695225/1061735/4894a34a-11fd-11e3-9d7e-b8df40e25a9a.png)

And side by side for better comparison.
![infantry_00](https://f.cloud.github.com/assets/2695225/1061729/ac427878-11fc-11e3-92cb-1c406b3e83a2.png) ![infantry_01](https://f.cloud.github.com/assets/2695225/1061731/e1c279f8-11fc-11e3-88f5-a7daf7e29595.png) ![infantry_02](https://f.cloud.github.com/assets/2695225/1061735/4894a34a-11fd-11e3-9d7e-b8df40e25a9a.png)