Update travis file

.travis.yml

@@ -22,7 +22,7 @@ matrix:
           sources:
             - ubuntu-toolchain-r-test
           packages:
-            - g++-8.1
+            - g++-8
       env:
         - MATRIX_EVAL="CC=gcc-8.1 && CXX=g++-8.1" BUILD_TYPE="Debug" DOUBLE_PRECISION="False"
 
@@ -301,18 +301,18 @@ script:
     - mkdir build_rp3d
     - cd build_rp3d
     - cmake -DCMAKE_BUILD_TYPE=${BUILD_TYPE} —DRP3D_DOUBLE_PRECISION_ENABLED=${DOUBLE_PRECISION} -DRP3D_COMPILE_TESTS=True -DRP3D_PROFILING_ENABLED=${PROFILER} -DRP3D_CODE_COVERAGE_ENABLED=${CODE_COVERAGE} ../
-    - make -j2
+    - cmake --build . -j2
     - make test ARGS="-V"
     - if [ "${VALGRIND}" == "True" ]; then
         valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes --verbose --error-exitcode=1 test/tests;
       fi
     - if [ "${CODE_COVERAGE}" == "False" ]; then
-        sudo make install;
+        sudo cmake --install .;
         cd ../;
         mkdir build_helloworld;
         cd build_helloworld;
         cmake -DCMAKE_BUILD_TYPE=${BUILD_TYPE} ../helloworld/;
-        make -j2;
+        cmake --build . -j2;
         ./helloworld;
       fi