Remove the logrus logger wrapper

cmd/dex/serve.go

connector/ldap/ldap_test.go

connector/saml/saml_test.go

pkg/log/logrus.go

pkg/log/logrus_test.go

server/api_test.go

server/rotation_test.go

server/server_test.go

storage/etcd/etcd_test.go

storage/kubernetes/storage_test.go

storage/memory/memory_test.go

storage/memory/static_test.go

storage/sql/config_test.go

storage/sql/migrate_test.go