Use files from `tests_old_dir`

Rather than from current series of tests.

Overlap/Tests/short_tests.json

@@ -464,7 +464,7 @@
             "$src_dir/Overlap/Analysis/report_graph.py",
             "--gv",
             "--merging",
-            "$PWD/EGr2nd15md4np3_cyclo/edgelist.csv"
+            "$tests_old_dir/EGr2nd15md4np3_cyclo/edgelist.csv"
 	]
     },
     "Report_graph_anti": {
@@ -472,7 +472,7 @@
             "$src_dir/Overlap/Analysis/report_graph.py",
             "--gv",
             "--merging",
-            "$PWD/EGr2nd15md4np3/edgelist.csv"
+            "$tests_old_dir/EGr2nd15md4np3/edgelist.csv"
 	]
     },
     "Plot_components": {