Stubbed out function template in the AST converter.

src/AST/Template.cs

@@ -193,6 +193,10 @@ namespace CppSharp.AST
     /// </summary>
     public class FunctionTemplate : Template
     {
+        public FunctionTemplate()
+        {
+        }
+
         public FunctionTemplate(Declaration decl)
             : base(decl)
         {

src/Core/Parser/ASTConverter.cs

@@ -1356,7 +1356,9 @@ namespace CppSharp
 
         public override AST.Declaration VisitFunctionTemplate(FunctionTemplate decl)
         {
-            throw new NotImplementedException();
+            var _decl = new AST.FunctionTemplate();
+            VisitTemplate(decl, _decl);
+            return _decl;
         }
 
         void VisitPreprocessedEntity(PreprocessedEntity entity, AST.PreprocessedEntity _entity)