Vendor psutils and remove neko

plugins/system/ps/process/process_posix_test.go

@@ -0,0 +1,19 @@
+// +build linux freebsd
+
+package process
+
+import (
+	"os"
+	"syscall"
+	"testing"
+)
+
+func Test_SendSignal(t *testing.T) {
+	checkPid := os.Getpid()
+
+	p, _ := NewProcess(int32(checkPid))
+	err := p.SendSignal(syscall.SIGCONT)
+	if err != nil {
+		t.Errorf("send signal %v", err)
+	}
+}