Added missing grails {} block for example mongo and redis configurations

refer to http://springsource.github.io/grails-data-mapping/mongo/manual/guide/2.%20Getting%20Started.html#2.3%20Advanced%20Configuration and https://github.com/grails-plugins/grails-redis for reference configurations.
Merge pull request #125 from andrew-wharton/master

Added missing grails {} block for example mongo and redis configurations