CI: Use Travis Homebrew addons instead install script

.travis.yml

@@ -46,6 +46,13 @@ jobs:
   - name: "macOS"
     stage: "Build"
     os: osx
+    addons:
+      homebrew:
+        packages:
+        - cmake
+        - libsndfile
+        - jack
+        - dylibbundler
     env:
     - INSTALL_DIR="sfizz-${TRAVIS_BRANCH}-${TRAVIS_OS_NAME}-${TRAVIS_CPU_ARCH}"
     install: .travis/install_osx.sh

.travis/install_osx.sh

@@ -3,9 +3,3 @@
 set -ex
 
 sudo ln -s /usr/local /opt/local
-brew cask uninstall --force java
-brew update
-brew upgrade cmake
-brew install python ||  brew link --overwrite python
-brew install jack
-brew install dylibbundler