Fix small typo in validator class.

Fixed a silly spelling typo inside the validator class.
Refactor tests for AttachmentConfigurationClass.

Refactored the tests for the AttachmentConfigurationClass.
Refactor style class.

- Refactored the style class so that style values can now be passed as an
array containing dimensions, quality, etc.
- Refactored tests for the Style class.
Remove extraneous convert_options key.

Removed the convert_options key from the default options since it's now
no longer needed.
Create tests for File factory.

Created tests for the faile factory.
Create tests for attachment factory.

Created attachment factory tests.
Clean up UploadedFileTest.

Cleaned up the UploadedFile test; made a few small changes, etc.
Create tests for the Storage factory class.

Created tests for the storage factory class.
Add typehinting to all classes.

Added typehinting to methods across all classes.
Refactor tests back into green.

Refactored the teset suite back into green.
Remove singleton methods from Stapler class.

Removed the singleton override methods from the Stapler class since it's
not longer a singleton implmentation.