Update travis llvm version
`llvm@7` was removed from the brew formulae so we have to upgrade
to the latest one which is `llvm@8`.
@@ -23,7 +23,7 @@ before_install:
# Download macOS specific extra dependencies.
- if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then git clone https://github.com/llvm-mirror/clang.git ~/llvm --branch master --single-branch --depth 1; fi
- if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install doxygen; fi
- - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install llvm@7; fi
+ - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install llvm@8; fi
- if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install thrift@0.9; fi
- if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then export PATH=/usr/local/Cellar/thrift@0.9/0.9.3/bin:$PATH; fi
- if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then which thrift; fi
