BUG: New test for 3D support

A newly added test that exercises 3D
support did not initialize the size
of the image in the 3rd dimension.

Changed 2D hard coded size to fill
in the size in all dimensions.

Modules/Numerics/Eigen/test/itkEigenAnalysis2DImageFilterTest.cxx

@@ -58,8 +58,7 @@ class EigenAnalysis2DImageFilterTester
 
     // Define their size, and start index
     mySizeType size;
-    size[0] = 2;
-    size[1] = 2;
+    size.Fill(2);
 
     myIndexType start;
     start.Fill(0);