Include math::Angle since it is used here (#649)

Signed-off-by: Michael Carroll <[email protected]>

Author: mjcarroll

graphics/src/SVGLoader.cc

@@ -23,9 +23,10 @@
 
 #include "tinyxml2.h"
 
+#include "gz/math/Angle.hh"
+
 #include "gz/common/Console.hh"
 #include "gz/common/Util.hh"
-
 #include "gz/common/SVGLoader.hh"
 
 using namespace gz;