Fix test.

Author: mcordingley

tests/MatrixTest.php

@@ -238,9 +238,9 @@ public function testDiagonal() {
 
         $this->assertEquals(1, $matrix->rows);
         $this->assertEquals(3, $matrix->columns);
-        $this->assertEquals(1, $matix->get(0, 1));
+        $this->assertEquals(1, $matix->get(0, 0));
         $this->assertEquals(5, $matix->get(0, 1));
-        $this->assertEquals(9, $matix->get(0, 1));
+        $this->assertEquals(9, $matix->get(0, 2));
     }
 
     public function testTrace() {