[CI/FS] Check that cmake build works with gcc-8

Author: Mike-Devel

Diff for: .travis.yml

@@ -102,6 +102,22 @@ matrix:
       compiler: clang++
       env: TOOLSET=clang CXXSTD=03,11,14,1z
 
+    - os: linux
+      compiler: g++
+      env: CMAKE=1
+      addons:
+        apt:
+          packages:
+            - libboost-filesystem-dev
+            - g++-8
+          sources:
+            - ubuntu-toolchain-r-test
+      install: true
+      script:
+        - mkdir __build__ && cd __build__
+        - cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=~ ..
+        - cmake --build . --target install
+
     - os: linux
       compiler: g++
       env: CMAKE=1