Remove boost serialization namespace.

Remove functions defined in boost serialization namespace.
It is no longer required since it has been replaced by cereal

Signed-off-by: Omar Shrit <omar@shrit.me>

src/mlpack/methods/ann/ffn.hpp

@@ -522,23 +522,6 @@ class FFN
 } // namespace ann
 } // namespace mlpack
 
-//! Set the serialization version of the FFN class.  Multiple template arguments
-//! makes this ugly...
-namespace boost {
-namespace serialization {
-
-template<typename OutputLayerType,
-         typename InitializationRuleType,
-         typename... CustomLayer>
-struct version<
-    mlpack::ann::FFN<OutputLayerType, InitializationRuleType, CustomLayer...>>
-{
-  BOOST_STATIC_CONSTANT(int, value = 2);
-};
-
-} // namespace serialization
-} // namespace boost
-
 // Include implementation.
 #include "ffn_impl.hpp"
 

src/mlpack/methods/ann/ffn_impl.hpp

@@ -23,8 +23,6 @@
 #include "visitor/set_input_height_visitor.hpp"
 #include "visitor/set_input_width_visitor.hpp"
 
-#include <boost/serialization/variant.hpp>
-
 namespace mlpack {
 namespace ann /** Artificial Neural Network. */ {