Merge github.com:grpc/grpc into error

src/python/grpcio/grpc/beta/implementations.py

templates/tools/dockerfile/node_deps.include

.../stress_test/grpc_interop_stress_ruby/Dockerfile.template

tools/dockerfile/interoptest/grpc_interop_node/Dockerfile

...dockerfile/interoptest/grpc_interop_node/build_interop.sh

...ockerfile/stress_test/grpc_interop_stress_node/Dockerfile

...ess_test/grpc_interop_stress_node/build_interop_stress.sh

...ockerfile/stress_test/grpc_interop_stress_ruby/Dockerfile

...ess_test/grpc_interop_stress_ruby/build_interop_stress.sh

tools/dockerfile/test/multilang_jessie_x64/Dockerfile

tools/dockerfile/test/node_jessie_x64/Dockerfile

tools/gce/linux_performance_worker_init.sh

tools/gcp/stress_test/run_ruby.sh

tools/run_tests/performance/run_worker_node.sh

tools/run_tests/run_tests.py

tools/run_tests/stress_test/configs/ruby.json