rust2018: remove extern crate

Signed-off-by: Levente Kurusa <lkurusa@acm.org>

tests/builder.rs

@@ -1,5 +1,4 @@
 //! Some simple tests covering the builder pattern for control groups.
-extern crate cgroups;
 use cgroups::*;
 use cgroups::cpu::*;
 use cgroups::devices::*;

tests/cgroup.rs

@@ -1,10 +1,6 @@
 //! Simple unit tests about the control groups system.
-extern crate cgroups;
 use cgroups::{Cgroup, CgroupPid};
 
-extern crate libc;
-extern crate nix;
-
 #[test]
 fn test_tasks_iterator() {
     let hier = cgroups::hierarchies::V1::new();

tests/cpuset.rs

@@ -1,5 +1,3 @@
-extern crate cgroups;
-
 use cgroups::cpuset::CpuSetController;
 use cgroups::error::ErrorKind;
 use cgroups::Cgroup;

tests/devices.rs

@@ -1,6 +1,5 @@
 //! Integration tests about the devices subsystem
 
-extern crate cgroups;
 use cgroups::devices::{DevicePermissions, DeviceType, DevicesController};
 use cgroups::{Cgroup, DeviceResource};
 

tests/pids.rs

@@ -1,14 +1,11 @@
 //! Integration tests about the pids subsystem
-extern crate cgroups;
 use cgroups::pid::{PidController, PidMax};
 use cgroups::Controller;
 use cgroups::{Cgroup, CgroupPid, PidResources, Resources};
 
-extern crate nix;
 use nix::sys::wait::{waitpid, WaitStatus};
 use nix::unistd::{fork, ForkResult, Pid};
 
-extern crate libc;
 use libc::pid_t;
 
 use std::thread;

tests/resources.rs

@@ -1,6 +1,4 @@
 //! Integration test about setting resources using `apply()`
-extern crate cgroups;
-
 use cgroups::pid::{PidController, PidMax};
 use cgroups::{Cgroup, PidResources, Resources};