Make Travis fail if couldn't build at all (#1307)

Author: DarthGandalf

.travis.yml

@@ -479,12 +479,12 @@ before_script:
 
 script:
   - if [[ "$TRAVIS_OS_NAME" == "linux" || "$TRAVIS_OS_NAME" == "osx" ]]; then
-      cmake -DENABLE_TESTING=1 -DCMAKE_BUILD_TYPE=Debug .. ;
-      make -j5 ;
+      cmake -DENABLE_TESTING=1 -DCMAKE_BUILD_TYPE=Debug .. &&
+      make -j5 &&
       ctest --output-on-failure ;
     fi
   - if [[ "$TRAVIS_OS_NAME" == "windows" ]]; then
-      cmake -DENABLE_TESTING=0 -G "$MSVCNAME" .. ;
+      cmake -DENABLE_TESTING=0 -G "$MSVCNAME" .. &&
       cmake --build . --target ALL_BUILD --config RelWithDebInfo --parallel ;
     fi
   #- ctest --output-on-failure