Merge #16438: travis: Print memory and number of cpus

fa4010e travis: Print memory and number of cpus (MarcoFalke)

Pull request description:

  For some reason it shows a different value than the one they advertise. This might be related to the flood of sanitizer warnings we see.

  https://docs.travis-ci.com/user/reference/overview/#virtualisation-environment-vs-operating-system

Top commit has no ACKs.

Tree-SHA512: 285bdf6e7fe29990b980acf64ca658f4319d17c770f45cfd4339244e6b7ec11b7a39b9c4a54e71415c32fef08ee5da75ab7171861905494d633631779480c146

Author: MarcoFalke

.travis/test_04_install.sh

@@ -6,6 +6,9 @@
 
 export LC_ALL=C.UTF-8
 
+free -m -h
+echo "Number of CPUs (nproc): $(nproc)"
+
 travis_retry docker pull "$DOCKER_NAME_TAG"
 
 export DIR_FUZZ_IN=${TRAVIS_BUILD_DIR}/qa-assets