* update dep golang.org/x/net
* Add stackdriver exporter support in pkg
* fix race and tests
* Use thread safe newMetricsExporter in tests
* address cr comments
* minor fix
* checkpoint
* Address cr comments
* add test for UpdateExporterFromConfigMap
* Move lock position
* add a test case for stackdriver error check
* minor change
* removing one test case since it seems app default creds exists for presubmit tests
* replace promSrvChan with promSrv as cr suggsted
* use a local var server for ListenAndServe
* add getter and setter for shared variables
* add func isMetricsConfigChanged and test
* address cr comments
* Update opencensus-go-exporter-stackdriver to v0.7.0
* Revert "Update opencensus-go-exporter-stackdriver to v0.7.0"
This reverts commit 9825f641f8.
* run update-deps.sh
* merge conflict
* run update-deps.sh
* Update Gopkg.toml so it doesn't have stackdriver exporter
* remove regex for metrics domain at pkg repo per cr comments
* merge conflict
akyyy