Re-use project partial for rendering explore projects from dashboard

For consistency with projects on dashboard after !1198

Before:

![Screenshot_2015-08-25_18.21.48](https://gitlab.com/gitlab-org/gitlab-ce/uploads/53bcf6909fe55b2e331ea6a720cb12ce/Screenshot_2015-08-25_18.21.48.png)

After:

![Screenshot_2015-08-25_18.20.22](https://gitlab.com/gitlab-org/gitlab-ce/uploads/fbda93828ec28ef1ac874d65b4a04c2b/Screenshot_2015-08-25_18.20.22.png)
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

See merge request !1200