message: Clean appveyour cache after dockers update
diff: @@ -34,3 +34,4 @@ by updates of docker files.
  04/25/2019: Updated dockers with LLVM ARM target
  05/01/2019: Updated dockers with LLVM AARCH64 target
  +06/07/2019: Updated LLVM 8.0 dockers after modyfing 8_0_r362675.patch
  