doc: mention move to clang-5.0 in the release notes
@@ -171,6 +171,7 @@ These notes are of interest for people developing Elektra:
- A build job checks if PRs modify the release notes. *(Markus Raab)*
- `clang` tests have been ported to the new build system *(Lukas Winkler et al)*
+- `clang-5.0` is now used for clang tests by the build system *(Lukas Winkler)*
- Several improvments to the build system have been implemented *(Lukas Winkler)*:
- Better Docker image handling
- abort of previously queued but unfinished runs on new commits
