This makes migrating to container-based infrastructure much easier (all
that is needed is adding "sudo: false" in the file).
Moreover installing the toolchain in a user directory fixes issues when
using the Trusty Beta environment: this toolchain broke the
already-installed Ubuntu packages (with for example policy version
issues between setfiles and checkpolicy). As the packaged tools (version
2.2) are much slower than the latest toolchain release on Trusty, it is
better to keep using the latest release.
As libcap-ng-dev package is not (yet? [1]) whitelisted in Travis-CI
container infrastructure, drop this package and do not build
policycoreutils/sandbox. Do not build policycoreutils/restorecond too as
it requires glib to be installed.
While at it, set the language as "generic" instead of "python".
[1] https://github.com/travis-ci/apt-package-whitelist/issues/1096
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>