travis osx: use newer version of xcode

see https://docs.travis-ci.com/user/reference/osx/#OS-X-Version I'm trying with version 9 instead of 8 (latest is 9.1)
andrie · Nov 17, 2017 · 6bc9338 · 6bc9338
1 parent 7a73422
commit 6bc9338
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/.travis.yml b/.travis.yml
@@ -23,9 +23,9 @@ matrix:
     r: devel
 
   - os: osx
-    osx_image: xcode8
+    osx_image: xcode9
     latex: false
-    
+
 r_build_args: '--no-build-vignettes'
 r_check_args: '--as-cran --ignore-vignettes --no-examples'
 
@@ -39,7 +39,7 @@ notifications:
   email:
     on_success: change
     on_failure: change
-    
+
 after_success:
   - test $TRAVIS_R_VERSION_STRING = "release" && Rscript -e 'withr::with_envvar(c(NOT_CRAN="true"), {covr::codecov()})'