Update alg_traits.jl

Author: ParasPuneetSingh

src/alg_traits.jl

@@ -118,6 +118,17 @@ Defaults to false.
 """
 requiresconstraints(opt) = false
 
+"""
+requiresderivative(opt)
+
+Trait declaration for whether an optimizer
+requires derivatives specified in
+`cons` in `OptimizationProblem`.
+
+Defaults to false.
+"""
+requiresderivative(opt) = false
+
 """
 allowscallback(opt)