API module
* Implemented the first cut for api module.
* It implements REST API for the employee-app using Spring MVC controllers
* It also provides persistence service for the models using Spring jdbc and MySQL
* Implemented transactions using Spring AOP
* Use Spring to implement dependency injection for DAOs, Services and Controllers
* Implemented DAO layer which provides CRUD operations for models using Spring jdbc
* Implemented RowMapper helper classes that translate JDBC ResultSet to model instance
* Implemented Service layer that manages transactions for service calls using Spring AOP
* Added controller layer for company model, to implement the REST resource for "Company"