travis: use gcc8

.travis.yml

@@ -55,8 +55,23 @@ before_install:
   - sudo apt-get update -qq
 #  - sudo apt-get upgrade
   - sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libavutil-dev libswresample-dev
+  - if [ ${TRAVIS_OS_NAME} = "linux" -a "$CC" = "gcc" ];
+    then
+        if [ "$BUILDDOC" = 1 ]; then
+            sudo apt-get install doxygen xsltproc;
+        fi;
+        sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test;
+        sudo apt-get update;
+        sudo apt-get install gcc-8 g++-8;
+        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-8 90;
+        sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-8 90;
+    fi
 
 install:
+  - if [[ ${COVERITY_BUILD_DISABLED} == 1 ]];
+    then
+        exit 0;
+    fi
 # OpenColorIO
   - sudo apt-get install cmake libtinyxml-dev liblcms2-dev libyaml-cpp-dev libboost1.60-dev
   - if [ ! -d "$HOME/ocio/lib" ]; then
@@ -167,10 +182,10 @@ addons:
     #- g++-5
     #- gcc-6
     #- g++-6
-    - gcc-7
-    - g++-7
-    #- gcc-8
-    #- g++-8
+    #- gcc-7
+    #- g++-7
+    - gcc-8
+    - g++-8
     #- libavcodec-dev
     #- libavformat-dev
     #- libswscale-dev