timestampEqual test fails on i386 Linux

[simevo]

launching tests with grunt-contrib-copy v1.0.0 fails on i386 Linux with:

...
Running "nodeunit:tests" (nodeunit) task
Testing copy_test.js.......F.
>> copy - timestampEqual
>> Error: 1493723278009 == 1493723278082
>>   at Object.timestampEqual (test/copy_test.js:92:10)
>>   at runCallback (timers.js:666:20)
>>   at tryOnImmediate (timers.js:639:5)
>>   at processImmediate [as _immediateCallback] (timers.js:611:5)

>> copy - timestampEqual
>> Error: 1493723278009 == 1493723278082
>>   at Object.timestampEqual (test/copy_test.js:93:10)
>>   at runCallback (timers.js:666:20)
>>   at tryOnImmediate (timers.js:639:5)
>>   at processImmediate [as _immediateCallback] (timers.js:611:5)

Warning: 2/17 assertions failed (19ms) Use --force to continue.

reproducible with node v4.8.2 and v6.10.2 on 4.9.0 kernels (both i386 and amd64) when run in a lxc container or within a VirtualBox VM, on an ext4 filesystem partition

for more details see the conversation in #268