* Use version to determine plugin protocol to use
* Remove field from ServeOpts
* Fix missing assignment, handle errors
* contraint -> constraint
* Inject the version string from the vault side
* Fix the version check
* Add grpc support check to database plugins
* Default to use grpc unless missing env var or fail on contraint check
* Add GRPCSupport test
* Add greater than test case
* Add go-version dep
* Add grpc plugins
* Add grpc plugins
* Translate wrap info to/from proto
* Add nil checks
* Fix nil marshaling errors
* Provide logging through the go-plugin logger
* handle errors in the messages
* Update the TLS config so bidirectional connections work
* Add connectivity checks
* Restart plugin and add timeouts where context is not availible
* Add the response wrap data into the grpc system implementation
* Add leaseoptions to pb.Auth
* Add an error translator
* Add tests for translating the proto objects
* Fix rename of function
* Add tracing to plugins for easier debugging
* Handle plugin crashes with the go-plugin context
* Add test for grpcStorage
* Add tests for backend and system
* Bump go-plugin for GRPCBroker
* Remove RegisterLicense
* Add casing translations for new proto messages
* Use doneCtx in grpcClient
* Use doneCtx in grpcClient
* s/shutdown/shut down/
* Don't call LeaseExtend on login renewal paths when period is provided
* WIP tests
* NoopBackend accept backend ttl values
* Test period value on credentials backend
* Use t.Fatalf instead
* Remove mockCoreExpiration
* Add login renewal test for approle backend
* Add resp.Auth.Period check on aws and cert backend tests
* Pass in approle's period via role's period
* Correctly set period in valid-role's role
* Add period renewal test using TestCluster and approle backend
* Check for ttl values after renewals on test
