prefer tee over cats

.gitlab-ci.yml

@@ -7,8 +7,7 @@ buildjob:
   - coqc -v
   - 'time make -j8 TIMED=y 2>&1 | tee build-log.txt'
   - 'grep Axiom build-log.txt && exit 1'
-  - 'cat build-log.txt  | egrep "[a-zA-Z0-9_/-]+ \(user: [0-9]" > build-time.txt'
-  - cat build-time.txt
+  - 'cat build-log.txt  | egrep "[a-zA-Z0-9_/-]+ \(user: [0-9]" | tee build-time.txt'
   only:
   - master
   - jh_simplified_resources