Increase max number of open files

Author: slandelle

travis/before_script.sh

@@ -1,6 +1,5 @@
 #!/bin/bash
-ulimit -u 514029
-ulimit -a
+ulimit -H -n 4000
 if ([ $TRAVIS_PULL_REQUEST = "false" ] && [ $TRAVIS_BRANCH = "master" ]); then
     ./travis/make_credentials.py
 fi