message: travis: try to install into /usr for gcc build
diff: @@ -76,15 +76,15 @@ install:
  script:
  - if [[ "${BUILD_TARGET}" = "gcc_build" ]]; then
  - make INSTALL_PREFIX=. EXTERNAL_DIR=external_example;
  - make default install;
  + make INSTALL_PREFIX=/usr EXTERNAL_DIR=external_example;
  + make install;
  make docs;
  make run_unit_tests;
  (cd example/takeoff_land && mkdir build && cd build && cmake .. && make);
  (cd example/fly_mission && mkdir build && cd build && cmake .. && make);
  (cd example/offboard_velocity && mkdir build && cd build && cmake .. && make);
  make clean;
  - make INSTALL_PREFIX=. BUILD_TYPE=Release;
  + make INSTALL_PREFIX=/usr BUILD_TYPE=Release;
  make install;
  make run_unit_tests;
  fi
  