Merge commit '5e623b8d' into p0-advance-protobuf-version

.travis.yml

Makefile

build.yaml

composer.json

doc/.gitignore

examples/cpp/helloworld/Makefile

examples/cpp/route_guide/Makefile

...les/objective-c/auth_sample/Misc/GoogleService-Info.plist

examples/php/composer.json

include/grpc++/impl/codegen/async_stream.h

include/grpc++/impl/codegen/async_unary_call.h

include/grpc++/impl/codegen/call.h

include/grpc++/impl/codegen/method_handler_impl.h

include/grpc++/impl/codegen/server_context.h

include/grpc++/impl/codegen/sync_stream.h

include/grpc++/server.h

include/grpc/impl/codegen/compression_types.h

include/grpc/impl/codegen/grpc_types.h

include/grpc/impl/codegen/port_platform.h

include/grpc/module.modulemap