Drop StatsBase compat bounds for tests (#76)

* Support StatsBase 0.34

* Un-bump version, remove StatsBase compat

Author: ararslan

Project.toml

@@ -8,7 +8,6 @@ DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
 [compat]
 julia = "1"
 DataStructures = "0.9, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18"
-StatsBase = "0.33"
 
 [extras]
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"