nodelet_core: 1.8.6-0 in 'hydro/distribution.yaml' [bloom]

Increasing version of package(s) in repository `nodelet_core` to `1.8.6-0`:

- upstream repository: git://github.com/ros/nodelet_core.git
- release repository: https://github.com/ros-gbp/nodelet_core-release.git
- distro file: `hydro/distribution.yaml`
- bloom version: `0.5.12`
- previous version for package: `1.8.5-0`

## nodelet

```
* Fix dependency version
* Contributors: Esteve Fernandez
```

## nodelet_core

- No changes

## nodelet_topic_tools

- No changes