- use google default creds, so the client works not only on GCE (e.g. it also reads env variable for creds).
- Change google default creds to use jwt directly if scope is not set.
- Leak check is disabled temporarily due to https://github.com/googleapis/google-cloud-go/issues/2417
* Modified tests to use tlogger.
* Fail on errors, with error expectations.
* Added expects and MixedCapsed grpclb_config tests
* Moved tlogger to grpctest, moved leakcheck tester to grpctest.go
* Added ExpectErrorN()
* Removed redundant leak checks
* Fixed new test
* Made tlogger globals into tlogger methods
* ErrorsLeft -> EndTest
* Removed some redundant lines
* Fixed error in test and empty map in EndTest
Changes to "xds_server" field in bootstrap file:
1. Field name is changed "xds_servers" (plural).
2. Field value should be a list of objects instead of a single object.
For now, we can ignore all entries except the first one. In the future, we will add support for falling back to a secondary server when the primary is not reachable.