Add Quaternion to rotation matrix

include/sta/math/quaternion.hpp

@@ -8,6 +8,7 @@
 #ifndef STA_PEAK_QUATERNION_HPP
 #define STA_PEAK_QUATERNION_HPP
 
+#include <sta/math/linalg/matrix.hpp>
 namespace sta
 {
 	namespace math {
@@ -55,11 +56,8 @@ namespace sta
 			 */
 			float norm();
 
-			/**
-			 * @brief 
-			 * 
-			 * @return Quaternion 
-			 */
+			matrix toRotationMatrix();
+
 			Quaternion normalized();
 
 			Quaternion conjugate();