Sails hook grunt need to update dependencies grunt-sync

**Sails version**: 1.0.2
**Node version**: 10.5.0
**NPM version**: 6.1.0
**DB adapter name**: N/A
**DB adapter version**: N/A
**Operating system**: Mac OS

I face problem on grunt task and it only happen on newest nodejs version 10.5.0 and no faced any issue on node 10.4.1 or previous version

```
Running "watch" task
Waiting...
>> File "assets/styles/project/_colors.scss" changed.
Running "less:dev" (less) task
>> 1 stylesheet created.

Running "sass:dev" (sass) task

Running "sync:dev" (sync) task
Warning: Cannot read property 'bigint' of undefined Use --force to continue.
```
Some guy from grunt told me that it already fixed on grunt-sync 0.8.0 but on sails-hook-grunt dependencies still using grunt-sync 0.6.2, so i can't update this dependencies.

So I think need to try upgrade dependencies for sails-hook-grunt.

Thank You