Add a start timestamp

Author: j-woz

workflows/p3b1_mlrMBO/swift/workflow3.swift

@@ -185,6 +185,8 @@ app (void o) make_dir(string dirname) {
 
 main() {
 
+  printf("WORKFLOW START: %0.3f", clock());
+
   assert(strlen(emews_root) > 0, "Set EMEWS_PROJECT_ROOT!");
 
   int ME_ranks[];