[WIP] Refactor - v7.0.0

Ok... Big changes here, @cordoval mind checking this over while i'm going through it?

Resolves #121 when complete. 

# Changes

1. Task is now called [JobDefinition][JobDefinition]

    A Task before, was basically a conversion of the Task configurations, to a Task object.
    *Job* Configurations will now be converted to a JobDefinition

2. Call is now called [TaskDefinition][TaskDefinition]

    This one was confusing. A Call was both a conversion of the Call configurations, and the code that does the call logic.
    *Task* Configurations will now be converted to a TaskDefinition

3. Call is now a Task

    Calls that were not the converted configuration items, will now be called Tasks.
    They have a new [Interface][TaskInterface], and a new [Abstract][AbstractTask] class to extend from

4. New [Exceptions][Exceptions]
    
    There are two new exceptions:
    * [RequiredParameterException][RequiredParameterException] - Thrown when a parameter is required, but not set
    * [ParameterNotFoundException][ParameterNotFoundException] - Thrown when a user asks for a parameter that isn't defined.

[JobDefinition]: //github.com/aequasi/bldr/tree/renameTaskAndCall/src/Definition/JobDefinition.php
[TaskDefinition]: //github.com/aequasi/bldr/tree/renameTaskAndCall/src/Definition/TaskDefinition.php
[TaskInterface]: //github.com/aequasi/bldr/tree/renameTaskAndCall/src/Task/TaskInterface.php
[AbstractTask]: //github.com/aequasi/bldr/tree/renameTaskAndCall/src/Task/AbstractTask.php
[Exceptions]: //github.com/bldr/tree/renameTaskAndCall/src/Exception/
[RequiredParameterException]: //github.com/aequasi/bldr/tree/renameTaskAndCall/src/Exception/RequiredParameterException.php
[ParameterNotFoundException]: //github.com/aequasi/bldr/tree/renameTaskAndCall/src/Exception/ParameterNotFoundException.php
as here