Add getAll interface

[lamchakchan]

Description

Added a getAll interface to address accessibility around ease of being able to pump all messages off of a queue.

Related Issue

• Working with error queues #66

Motivation and Context

The use of subscribe is not sufficient for use cases when the need for a vanilla data pump is necessary. Cases where we only want to listen for messages off of a queue and do not want to associate any routeKey mapping.

Types of changes

• Documentation only (no changes to either lib/ or test/ files)
• Bug fix (non-breaking change which fixes an issue. you didn't modify existing tests)
• New feature (non-breaking change which adds functionality. you added at least one new test)
• Breaking change (fix or feature that would cause existing functionality to change. you had to modify existing tests.)

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the Hapi.js style guide.
• I have updated the documentation as needed.
• I have added tests to cover my changes.
• All new and existing tests passed.