travis: run tests on trusty instead of precise

precise's libc headers are extremly old and don't define SYS_*. trusty's
do, so let's run the travis tests there.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

.travis.yml

@@ -9,3 +9,5 @@ before_install:
   - sudo apt-get install -qq protobuf-c-compiler libprotobuf-c0-dev libaio-dev libprotobuf-dev protobuf-compiler python-ipaddr libcap-dev libnl-3-dev
 script:
   - "bash -ex scripts/travis-ci.sh"
+sudo: required
+dist: trusty