Link to `Try it out` : plang1.cs.usyd.edu.au’s server IP address could not be found.

[mingodad]

When clicking in Try it out on https://souffle-lang.github.io/ I'm getting plang1.cs.usyd.edu.au’s server IP address could not be found.

[mingodad]

Also the link to DOOP in https://souffle-lang.github.io/docs.html is broken it seems that now it's at https://github.com/plast-lab/doop

[quentin]

Related #166