Stackdriver logging

[brahtala]

Please update the logback spring stackdriver example with the latest version of GCP dependencies.
In newer versions <include resource="org/springframework/cloud/gcp/logging/logback-appender.xml" />
must be changed to com/google/cloud/spring/logging/logback-json-appender.xml.
in: examples/stackdriver-logging-121/src/main/resources/logback-spring.xml .

And thanks for the examples :)

[elefeint]

Thanks! I am happy to accept a pull request, but I don't currently work in this stack, so I am not up to date on the latest.