Add unittest
[ 23s] + ./num_cpus
[ 23s]
[ 23s] running 15 tests
[ 23s] test linux::tests::v1::test_cgroup_cpu_quota ... ok
[ 23s] test linux::tests::v1::test_cgroup_cpu_quota_ceil ... ok
[ 23s] test linux::tests::v1::test_cgroup_cpu_quota_divide_by_zero ... ok
[ 23s] test linux::tests::v1::test_cgroup_mount ... ok
[ 23s] test linux::tests::v1::test_load_mountinfo ... ok
[ 23s] test linux::tests::v1::test_load_subsys ... ok
[ 23s] test linux::tests::v2::test_cgroup_cpu_quota ... ok
[ 23s] test linux::tests::v2::test_cgroup_cpu_quota_ceil ... ok
[ 23s] test linux::tests::v2::test_cgroup_cpu_quota_divide_by_zero ... ok
[ 23s] test linux::tests::v2::test_cgroup_mount ... ok
[ 23s] test linux::tests::v2::test_load_mountinfo ... ok
[ 23s] test linux::tests::v2::test_load_subsys ... ok
[ 23s] test linux::tests::v2::test_load_subsys_multi ... ok
[ 23s] test tests::test_get ... ok
[ 23s] test tests::test_get_physical ... ok
[ 23s]
[ 23s] test result: ok. 15 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.05s