Added matrix matrix multiplication unit tests.

Fixed bug in matrix multiplication.

src/Numerics/LinearAlgebra/Double/Matrix.cs

@@ -812,7 +812,7 @@ namespace MathNet.Numerics.LinearAlgebra.Double
                         {
                             s += this.At(j, l) * other.At(l, i);
                         }
-                        result.At(i, j, s);
+                        result.At(j, i, s);
                     }
                 });
             }

src/UnitTests/LinearAlgebraTests/Double/MatrixTests.cs

@@ -666,7 +666,7 @@ namespace MathNet.Numerics.UnitTests.LinearAlgebraTests.Double
         [Row("Wide2x3", "Tall3x2")]
         [Row("Tall3x2", "Wide2x3")]
         [MultipleAsserts]
-        public void CanMultiplyMatrixWithMatrix(string nameA, string nameB)
+        public void CanMultiplyMatrixWithMatrixIntoResult(string nameA, string nameB)
         {
             Matrix A = testMatrices[nameA];
             Matrix B = testMatrices[nameB];