update dropwizard-example README.md to current version

silly little text files don't keep up with the project
change 0.3.0 to 0.7.0
Add ObjectMapperFactory#configure

Provides a means to configure existing `ObjectMapper` instances using
the Dropwizard `ObjectMapperFactory`.

Breaks out the code to configure instances from
`ObjectMapperFactory#build()` in to `ObjectMapperFactory#configure()`.
Extended hibernate configuration.

Allows HibernateBundle to configure the SessionFactory in ways that are
not possible using standard properties.

Specifically NamingStrategy and any other configuration outside of
org.hibernate.cfg.Environment.
Merge pull request #290 from nicktelford/feature/configure-objectmapper

Add ObjectMapperFactory#configure
Merge pull request #291 from vadims/hibernate-configure

Extended hibernate configuration.
Merge pull request #289 from littleidea/example_readme_version

update dropwizard-example README.md to current version