Add a default delete override for the interface

Add bazel tests to Kokoro

Split up macos basictests into dbg and opt and set num of jobs to 1.

Prepopulate more pip packages on kokoro linux

Make tsi handshaker result unused bytes const

Node: document that root_certs in createSsl is optional

It appears that omitting it causes grpc to use the hosts' default cert data.
This was brought up (as I had implemented this method incorrectly) in:
https://github.com/mixer/etcd3/issues/28#issuecomment-319510441

Auto_set_flakes also reruns tests that timeout

Pre-populate xdg-cache-home to deflake python kokoro build

Updating roots from Mozilla.

Fix implicit fallthrough warning on GCC 7.x

Flow Control

Fix a racey test in ruby

Node: replace custom deprecation warning with existing solution

Actually test grpc++_unsecure

Add a GrpcLibraryInitializer to client_context.cc

Initialize initiating_exec_ctx_or_null

Fix leak if duplicated static metadata

Convenient Fuzz Tracing

Add comment and test for API of a parameter to grpc_call_cancel_with_status

Get more useful debug info out of Jenkins

Fix two memory leak points in ObjC