Text Diamond Kata

Here’s a sample solution for the Text Diamond Kata that I’m using with cyber-dojo:

Given a letter print a diamond starting with 'A' 
with the supplied letter at the widest point. 
For example: print-diamond 'E' prints


    A
   B B
  C   C
 D     D
E       E
 D     D
  C   C
   B B
    A

This sample deliberately doesn’t used recursion (the group is learning basic algorithm handling), and is written in C# using MsTest as the test framework.