Upgrade slopop to relsurv v2.3-2 (#31)

* update slopop to relsurv v2.3-2

* up version

Author: lrnv

Project.toml

@@ -1,7 +1,7 @@
 name = "RateTables"
 uuid = "d40fb65e-c2ee-4113-9e14-cb96ca0acb32"
 authors = ["Oskar Laverny <oskar.laverny@univ-amu.fr> and contributors"]
-version = "0.2.2"
+version = "0.2.3"
 
 [deps]
 CSV = "336ed68f-0bac-5ca0-87d4-7b16caf5d00b"