ci: use homebrew addon to simplify shell scripts

.travis.yml

@@ -117,6 +117,11 @@ addons:
       - unzip
       - valgrind
       - xclip
+  homebrew:
+    update: true
+    packages:
+      - ccache
+      - ninja
 
 branches:
   only:

ci/before_install.sh

@@ -7,10 +7,6 @@ if [[ "${CI_TARGET}" == lint ]]; then
   exit
 fi
 
-if [[ "${TRAVIS_OS_NAME}" == osx ]]; then
-  >/dev/null brew update
-fi
-
 echo 'python info:'
 (
   2>&1 python --version || true

ci/install.sh

@@ -8,8 +8,6 @@ if [[ "${CI_TARGET}" == lint ]]; then
 fi
 
 if [[ "${TRAVIS_OS_NAME}" == osx ]]; then
-  brew install ccache
-  brew install ninja
   export PATH="/usr/local/opt/ccache/libexec:$PATH"
 fi