Merge pull request #2288 from gennadiycivil:master

PiperOrigin-RevId: 253652550

.travis.yml

@@ -11,28 +11,26 @@ language: cpp
 matrix:
   include:
     - os: linux
-      dist: trusty
       sudo: required
-      group: deprecated-2017Q3
       before_install: chmod -R +x ./ci/*platformio.sh 
       install: ./ci/install-platformio.sh
       script: ./ci/build-platformio.sh      
     - os: linux
+      dist: xenial
       compiler: gcc
       sudo : true
       install: ./ci/install-linux.sh && ./ci/log-config.sh
       script: ./ci/build-linux-bazel.sh
     - os: linux
+      dist: xenial
       compiler: clang
       sudo : true
       install: ./ci/install-linux.sh && ./ci/log-config.sh
       script: ./ci/build-linux-bazel.sh
     - os: linux
-      group: deprecated-2017Q4
       compiler: gcc
       env: BUILD_TYPE=Debug VERBOSE=1 CXX_FLAGS=-std=c++11 
     - os: linux
-      group: deprecated-2017Q4
       compiler: clang
       env: BUILD_TYPE=Release VERBOSE=1 CXX_FLAGS=-std=c++11 -Wgnu-zero-variadic-macro-arguments
     - os: linux