message: Update AppVeyor config to use 1.15 stable
diff: @@ -11,7 +11,7 @@ environment:
  TARGET: x86_64-pc-windows-msvc
  HDF5_BINDIR: "C:\\Program Files\\HDF_Group\\HDF5\\1.8.17\\bin"
  matrix:
  - - CHANNEL: 1.13.0
  + - CHANNEL: 1.15.0
  FEATURES: ""
  - CHANNEL: beta
  FEATURES: ""
  