Make sure that bandicoot is included if needed.

Author: rcurtin

tests/test_types.cpp

@@ -7,6 +7,10 @@
  * the 3-clause BSD license along with ensmallen.  If not, see
  * http://www.opensource.org/licenses/BSD-3-Clause for more information.
  */
+#if defined(ENS_USE_COOT)
+  #include <armadillo>
+  #include <bandicoot>
+#endif
 #include <ensmallen.hpp>
 #include "test_types.hpp"