Merge github.com:grpc/grpc into grand-unified-closures

.gitmodules

.travis.yml

examples/cpp/helloworld/Makefile

examples/cpp/route_guide/Makefile

examples/objective-c/auth_sample/Podfile

examples/objective-c/helloworld/Podfile

examples/objective-c/route_guide/Podfile

examples/php/composer.json

examples/python/helloworld/run_codegen.sh

examples/python/route_guide/run_codegen.sh

gRPC-Core.podspec

gRPC-ProtoRPC.podspec

gRPC-RxLibrary.podspec

gRPC.podspec

include/grpc/module.modulemap

package.json

src/core/lib/security/transport/client_auth_filter.c

src/core/lib/surface/channel.c

src/node/health_check/LICENSE

src/node/health_check/health.js