Merge pull request #9 from JuliaGraphs/dependabot/julia/DataStructures-tw-0.18.1-and-0.19-and-0.19

Update DataStructures requirement from ^0.18.1, 0.19 to ^0.18.1, 0.19, 0.19

Author: djukic14

Project.toml

@@ -15,7 +15,7 @@ GraphsColoringGraphs = ["Graphs"]
 
 [compat]
 Aqua = "0.8"
-DataStructures = "^0.18.1, 0.19"
+DataStructures = "^0.18.1, 0.19, 0.19"
 Graphs = "1"
 JLD2 = "0.6"
 JuliaFormatter = "2.1"