CompatHelper: bump compat for Flux to 0.15, (keep existing compat)

Author: CompatHelper Julia

Project.toml

@@ -25,7 +25,7 @@ Constraints = "0.5"
 DataFrames = "1"
 Dictionaries = "0.4"
 Evolutionary = "0.11"
-Flux = "0.13, 0.14"
+Flux = "0.13, 0.14, 0.15"
 LocalSearchSolvers = "0.4"
 Memoization = "0.2"
 PrettyTables = "2"