Fixes for control systems AND SVD and QR decomposition (#9)

Reviewed-on: #9
Co-authored-by: Cynopolis <quinn.henthorne@gmail.com>

unit-tests/matrix-timing-tests.cpp

@@ -76,7 +76,8 @@ TEST_CASE("Timing Tests", "Matrix") {
 
   SECTION("Determinant") {
     for (uint32_t i{0}; i < 1000000; i++) {
-      float det1 = mat4.Det();
+      float det = mat4.Det();
+      (void)det;
     }
   }