Add clang formatting style

1 job for !20 with patch6.3 in 12 minutes and 46 seconds (queued for 1 second)
Status Job ID Name Coverage
failed #1598
linux kf5-qt5 qt5.10


Name Stage Failure
linux kf5-qt5 qt5.10 Build
make[2]: *** No rule to make target 'rttr_project-prefix/lib/librttr_core.a', needed by 'runTests'.  Stop.
make[2]: *** Waiting for unfinished jobs....
[ 98%] Building CXX object CMakeFiles/runTests.dir/runTests_autogen/mocs_compilation.cpp.o
make[1]: *** [CMakeFiles/Makefile2:140: CMakeFiles/runTests.dir/all] Error 2
make: *** [Makefile:141: all] Error 2
Uploading artifacts...
WARNING: JUnitTestResults.xml: no matching files
ERROR: No files to upload
ERROR: Job failed: exit code 1