Let Travis run for CMake test and lint.sh

.travis.yml

@@ -13,6 +13,8 @@ before_install:
   - bundle exec pod install --project-directory=Example --repo-update
   - bundle exec pod install --project-directory=Firestore/Example --no-repo-update
   - brew install clang-format
+  - brew install cmake
+  - brew install go # Somehow the build for Abseil requires this.
   - echo "$TRAVIS_COMMIT_RANGE"
   - echo "$TRAVIS_PULL_REQUEST"
   - |
@@ -31,6 +33,7 @@ script:
   - "! git grep -I ' $' ':(exclude)Firestore/Protos/nanopb'"
   - "! git grep -EL --name-only 'Copyright [0-9]{4}.*Google' | grep -v third_party | egrep '\\.(m|h|cc|mm|c)$'"
   - ./scripts/style.sh test-only # Validate clang-format compliance
+  - ./scripts/lint.sh # Google C++ style compliance
   - |
     if [ $SKIP_FIREBASE != 1 ]; then
       ./test.sh

Firestore/test.sh

@@ -38,6 +38,22 @@ test_iOS() {
     | xcpretty
 }
 
+test_CMake() {
+  echo "set cmake build" && \
+    mkdir build && \
+    cd build && \
+    cmake .. || \
+    exit 1
+
+  echo "initial cmake build" && \
+    make -j all || \
+    exit 2
+
+  echo "test Firestore cmake build" && \
+    cd Firestore && \
+    make test
+}
+
 test_iOS; RESULT=$?
 if [[ $RESULT == 65 ]]; then
   echo "xcodebuild exited with 65, retrying"
@@ -46,4 +62,8 @@ if [[ $RESULT == 65 ]]; then
   test_iOS; RESULT=$?
 fi
 
-exit $RESULT
+if [ $RESULT != 0 ]; then exit $RESULT; fi
+
+test_CMake; RESULT=$?
+
+if [ $RESULT != 0 ]; then exit $RESULT; fi