Constructor autowiring (#56)

[bjansen]

The main change is that endpoints are instantiated using applicationContext.getAutowireCapableBeanFactory().createBean(clazz) rather than using reflection directly.

Actual autowiring is tested in WeatherServiceEndpointSystemTest.java.

Note that endpoints don't necessarily need the @Autowired annotation, Spring will also manage non-annotated constructors as long as the dependencies exist.

[marcopaga]

Thank you @bjansen. This make instatiating cleaner. Cool, that you brought this up and implemented it 👍

[bjansen]

My pleasure!