Merge pull request #196 from PQClean/fix_travis

Update OSX image

.travis.yml

@@ -2,7 +2,7 @@ matrix:
   include:
     - name: "MacOS + Clang"
       os: osx
-      osx_image: xcode10.1
+      osx_image: xcode10.2
       compiler: clang
       before_install:
         - pip3 install -r requirements.txt
@@ -23,7 +23,7 @@ matrix:
             - astyle
     - name: "MacOS + GCC8"
       os: osx
-      osx_image: xcode10.1
+      osx_image: xcode10.2
       compiler: gcc
       addons:
         homebrew:
@@ -48,6 +48,12 @@ matrix:
         - "cd test && travis_wait 60 python3 -m nose --rednose --verbose"
 
 
-cache: pip
+cache:
+  directories:
+    - $HOME/Library/Caches/pip
+    - $HOME/Library/Caches/Homebrew
+
+before_cache:
+  - brew cleanup
 
 #  vim: set ft=yaml ts=2 sw=2 tw=0 et :