Predefined dimensions moved to a dedicated directory

test_package/test_package.cpp

@@ -20,7 +20,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-#include <units/velocity.h>
+#include <units/dimensions/velocity.h>
 #include <iostream>
 
 namespace stde = std::experimental;