bug fix + enhancement + cleanup

Author: sl-solution

src/InMemoryDatasets.jl

@@ -160,7 +160,7 @@ include("dataset/transpose.jl")
 # joins
 include("join/join.jl")
 include("join/join_dict.jl")
-include("join/asof.jl")
+include("join/closejoin.jl")
 include("join/update.jl")
 include("join/main.jl")