travis: add ubuntu 18.04 compilation test

Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
 Reviewed-by: Dmitry Eremin-Solenikov <dmitry.ereminsolenikov@linaro.org>

.travis.yml

@@ -43,6 +43,7 @@ env:
         # for individual commit validation. But you you want to track tests history
         # you need generated new one at https://codecov.io specific for your repo.
         - CODECOV_TOKEN=a733c34c-5f5c-4ff1-af4b-e9f5edb1ab5e
+        - UBUNTU_VERS="16.04"
     matrix:
         - CONF=""
         - CONF="--disable-abi-compat"
@@ -61,6 +62,7 @@ env:
         - CONF="--disable-host-optimization --disable-abi-compat"
         - CONF="--enable-pcapng-support"
         - CONF="--without-openssl"
+        - CONF="" UBUNTU_VERS="18.04"
 
 compiler:
         - gcc
@@ -85,14 +87,14 @@ script:
                docker run  -i -t -v `pwd`:/odp
                  -e CC="${CC}"
                  -e CONF="${CONF}"
-                 ${DOCKER_NAMESPACE}/travis-odp-lng-ubuntu_16.04 /odp/scripts/ci/build_${CROSS_ARCH}.sh ;
+                 ${DOCKER_NAMESPACE}/travis-odp-lng-ubuntu_${UBUNTU_VERS} /odp/scripts/ci/build_${CROSS_ARCH}.sh ;
           else
                echo "Running test" ;
                docker run --privileged -i -t
                  -v `pwd`:/odp --shm-size 8g
                  -e CC="${CC}"
                  -e CONF="${CONF}"
-                 ${DOCKER_NAMESPACE}/travis-odp-lng-ubuntu_16.04 /odp/scripts/ci/check.sh ;
+                 ${DOCKER_NAMESPACE}/travis-odp-lng-ubuntu_${UBUNTU_VERS} /odp/scripts/ci/check.sh ;
           fi
 jobs:
         include: