AppVeyor: build changed to release versions of R and Bioc.

Author: andzajan

appveyor.yml

@@ -19,8 +19,8 @@ environment:
   # see https://github.com/krlmlr/r-appveyor#readme for details
   # USE_RTOOLS: true
   # R_REMOTES_STANDALONE: true
-  R_VERSION: devel
-  BIOC_USE_DEVEL: TRUE
+  R_VERSION: release
+  BIOC_USE_DEVEL: false
   USE_RTOOLS: true
   PKGTYPE: both