Sometimes it's required to modify some parts of the Citrix build on
their own which is why `{pre,post}Install` hooks can be quite helpful.
Additionally some corporate clients use their own certificates that
aren't stored as trusted ones in the `cacert` package with all of the
trusted certs by Mozilla.
Now it's possible to add custom certs like this:
``` nix
with import <nixpkgs> { config.allowUnfree = true; };
let path = ../../Downloads/custom-corporate-cert.pem; in
citrix_receiver.override {
extraCerts = [ path ];
}
```
