Update CMakeLists.txt

ros2 use c++17
cmake <3.8 is deprecaded

Author: mosfet80

CMakeLists.txt

@@ -20,13 +20,13 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.8)
 project(backward_ros)
 
 include(cmake/BackwardConfig.cmake)
 
 set(CMAKE_CXX_STANDARD_REQUIRED True)
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 17)
 
 if(WIN32)
   # set the same behavior for windows as it is on linux