Library Exception Class.

Create a new class that extends the default Exception class so that we have complete control over Exceptions, should we wish to add functionality later on.
Replace the example unit test with one for the Exception class.
Request class.

Add the base class for all service calls to Experian.
Update the README.

Updated the README to include future functionality that will get written down the line somewhere.
Update Request class.

Updated Request class to look for sub-classes under the namespace of \Nosco\Request\Partial, as that is the class that they will extend.
Also updated the DocComment to specify that the exception returned is actually \Nosco\Exception.