Follow the v3 specs

[dannyhajj]

Type of change

• New feature
• Bug fix
• Security patch
• Documentation update

Description

A bit of rewriting of the package, mainly.

• Most of the tests were not running at all, as the functions were breaking out of the test method when the ssn was invalid, which is the case starting from the first time in the list of ssns.
• Made the package align more with the v3 versions and implemented the get_date method from v3.1.
• It is still missing the Interim-Number functionality, but I have to increase the minor version as it has some breaking changes of undocumented functionality, which should not be used outside of the library (next point).
• I prepended several methods with an underscore (_) that are not part of the meta documentation. These are somewhat annoying as IDE will show them in their auto-completion functionality. Having the underscore indicates that a method is only intended for internal use, as defined by PEP8.

Missing functionality

• More functionality needs to be tested, such as the is_coordination_number() method and the new get_age() method. But the PR was getting bigger and bigger and the tests were not working I decided to stop there and those can be done in a different PR.
• Parsing Interim-Number

Related issue

N/A

Motivation

Tests were not working.

Checklist

• I have read the CONTRIBUTING document.
• I have read and accepted the Code of conduct
• Tests pass.
• Style lints passes.
• Documentation of new public methods exists.

• New tests added which covers the added code.
• Documentation is updated.
• This PR includes breaking changes (but only undocumented functionality).

[frozzare]

Looks good from my basic python knowledge! Awesome work 😄