coverity_scan matrix use gcc-7

.travis.yml

@@ -220,16 +220,23 @@ matrix:
     - os: osx
       env: OSX=1 STDFLAG=-std=c++11
     - compiler: gcc
-      env: COVERITY_SCAN=1
+      env:
+        - COVERITY_SCAN=1
+        - CC=gcc-7
+        - CXX=g++-7
       addons:
-        apt: *apt-global
+        apt:
+          sources: *apt-common-sources
+          packages:
+            - gcc-7
+            - g++-7
         coverity_scan:
           project:
             name: "srz-zumix/iutest"
             description: "iutest c++ testing framework"
           notification_email: zumix.cpp@gmail.com
-          build_command_prepend: "cov-configure --comptype gcc --compiler gcc-8 --template && cd ./test"
-          build_command: make -j4 coverity_scan STDFLAG=-std=c++03
+          build_command_prepend: "cov-configure --comptype gcc --compiler gcc-7 --template && cd ./test"
+          build_command: make -j4 coverity_scan STDFLAG=-std=c++17
           branch_pattern: master|.*coverity_scan.*
     # Sanitize
     #- compiler: clang