source added

package.json

@@ -17,5 +17,9 @@
         "src-dir": "src",
         "options": "-m100 -dInt",
         "modules":  [ "Combinatorial", "Nat", "ShowS", "Sort" ]
+    },
+    "source": {
+      "git": "https://git.ps.informatik.uni-kiel.de/curry-packages/base.git",
+      "tag": "$version"
     }
 }