change batmen commit and batsim release in nix file

default.nix

@@ -5,35 +5,13 @@
 with kapack.pkgs;
 
 let self = rec {
-  my-simgrid = kapack.simgrid-light.overrideAttrs(old: rec {
-    version = "33035e7eeaee7a34efd75d675555eec32d34856a";
-    src = kapack.pkgs.fetchgit rec {
-      url = "https://framagit.org/simgrid/simgrid.git";
-      rev = version;
-      sha256 = "0a2w8qzw5sa7rccn6m0r6ifjcvzyadijfg8p3g2j6nhpav2rm2l7";
-    };
-    patches = [];
-    doCheck = false;
-  });
-
-  my-batsim = (kapack.batsim.override { simgrid = my-simgrid; })
-  .overrideAttrs(old: rec {
-    version = "ccd208711985af2b10d726a29bd9396e4da8d6a6";
-    src = kapack.pkgs.fetchgit rec {
-      url = "https://framagit.org/batsim/batsim.git";
-      rev = version;
-      sha256 = "0sf6i70qh8jfl2vhmrvm9bjrwda4cf15v5xbpnq5gfb57fq87n8v";
-    };
-    patches = [];
-  });
-
-  my_batsched = kapack.batsched.overrideAttrs (attr: rec {
+  batmen = kapack.batsched.overrideAttrs (attr: rec {
     name = "batmen";
-    version = "b63e95fad46962572b1f1d6db5bda979ca20dae0"; # commit "clean nix file and update README"
+    version = "8e22ee446840b0baf69ba646054d9f074b1ecf31"; # commit "added a simple speedup model in n^alpha"
     src = kapack.pkgs.fetchgit rec {
       url = "https://gitlab.irit.fr/sepia-pub/mael/batmen.git";
       rev = version;
-      sha256 = "1q2s1f68j4wd8vzzzirpjp7851l342hq6dvd9ky5g62zdps5mqlj";
+      sha256 = "0b8rycph0s2ir176582llyqyszqznlrsrc10q2hzjq9wmggzkv3g";
 
     };
   });
@@ -42,9 +20,9 @@ let self = rec {
     name = "exp_env";
     buildInputs = [
       # simulator
-      my-batsim
+      kapack.batsim
       # scheduler implementations
-      my_batsched
+      batmen
       # misc. tools to execute instances
       kapack.batexpe
       kapack.evalys