Update Travis CI configuration.

* Use Ubuntu 18.04 and LLVM 9 on Travis.
* Fix bash conditionals: [ a == b ] should be [ a = b ].

PiperOrigin-RevId: 271898719

.travis.yml

@@ -3,8 +3,8 @@
 # This file can be validated on: http://lint.travis-ci.org/
 
 language: cpp
-dist: xenial
-osx_image: xcode10.2
+dist: bionic
+osx_image: xcode10.3
 
 compiler:
 - gcc
@@ -20,10 +20,11 @@ env:
 addons:
   apt:
     sources:
-    - llvm-toolchain-xenial-8
-    - ubuntu-toolchain-r-test
+    - sourceline: 'deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main'
+      key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
+    - sourceline: 'ppa:ubuntu-toolchain-r/test'
     packages:
-    - clang-8
+    - clang-9
     - cmake
     - gcc-9
     - g++-9
@@ -38,8 +39,8 @@ addons:
     - crc32c
     - gcc@9
     - gperftools
-    - kyotocabinet
-    - llvm@8
+    - kyoto-cabinet
+    - llvm@9
     - ninja
     - snappy
     - sqlite3
@@ -48,7 +49,7 @@ addons:
 install:
 # The following Homebrew packages aren't linked by default, and need to be
 # prepended to the path explicitly.
-- if [ "$TRAVIS_OS_NAME" == "osx" ]; then
+- if [ "$TRAVIS_OS_NAME" = "osx" ]; then
     export PATH="$(brew --prefix llvm)/bin:$PATH";
   fi
 # /usr/bin/gcc points to an older compiler on both Linux and macOS.
@@ -58,8 +59,8 @@ install:
 # Homebrew's llvm package doesn't ship a versioned clang++ binary, so the values
 # below don't work on macOS. Fortunately, the path change above makes the
 # default values (clang and clang++) resolve to the correct compiler on macOS.
-- if [ "$TRAVIS_OS_NAME" == "linux" ]; then
-    if [ "$CXX" = "clang++" ]; then export CXX="clang++-8" CC="clang-8"; fi;
+- if [ "$TRAVIS_OS_NAME" = "linux" ]; then
+    if [ "$CXX" = "clang++" ]; then export CXX="clang++-9" CC="clang-9"; fi;
   fi
 - echo ${CC}
 - echo ${CXX}