Update Project.toml

Author: mykelk

Project.toml

@@ -24,7 +24,7 @@ Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
 
 [compat]
-DataFrames = "0.21,0.22"
+DataFrames = "0.21"
 DataStructures = "0.11,0.12,0.13,0.14,0.15,0.16,0.17,0.18"
 Discretizers = "3.0"
 Distributions = "0.17,0.18,0.19,0.20,0.21,0.22,0.23,0.24"