Batch - API

1. Created class hierarchy for Batch - API
2. Added UnknownCommandStrategy for any unknown command given to Batch-API
3. Added CreateClientCommandStrategy to create a new client using Batch-API
4. Added integration and unit tests for the existing classes in Batch-API

Input format for the API: https://mifosforge.jira.com/wiki/display/projects/Batch+API+Solution+Concept#BatchAPISolutionConcept-Definition