Add simple logo.

4 jobs from master in 4 minutes 2 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #3260
build_cmake

00:44

 
  Test
passed #3261
run_tests

00:44

 
  Sanitizer
passed #3263
run_address_sanitizer

01:33

passed #3262
run_thread_sanitizer

00:59