Faker

* Change blood group from ``0`` (zero) to ``O`` (capital letter O). Some
locales do use 'zero', but ``O`` is more common and it is the medical
standard. Thanks mohi7solanki.
* Fix alpha-2 country code for Haiti. Thanks sevens-ef for the report.
* Fix abbreviation for Nunavut. Thanks straz for the report.
* Standardized ``postcode`` in address providers. Now all locales are
guaranteed to have a ``postcode`` method and may have a localized alias for
it (eg: ``zipcode``). Thanks straz for the report.
* Fix typo in ``pt_BR`` Person perovider. Thanks Nichlas.
* Fix timezone handling. Thanks Fraterius.
* Use tzinfo when provided in ``date_of_birth``. Thanks Kelledin.

* Add ``ein``, ``itin`` and refactored ``ssn`` Provider for ``en_US``.
Thanks crd.
* Add ``job`` provider for ``zh_CN``. Thanks ramwin.
* Add ``date_of_birth`` provider. Thanks cdr.
* Add alpha-3 representation option for ``country-code`` provider. Thanks cdr.

* Fix test for CPF (Brazilian SSN). Thanks Rubens Takiguti Ribeiro.
* Fix Canadian SIN generation. Thanks crd.
* Fix Norwegian SSN date portion. Thanks frangiz.
* Add ``start_datetime`` argument for ``unix_time()``. Thanks crd.

* Change logging level to ``DEBUG``.

* Add possibility to make artificial ssn numbers for ``FI_fi``. Thanks kivipe.
* Update ``ko_KR`` person data based on statistics. Thanks unace.
* Improved logging. Thanks confirmationbias616.

* Add ``no_NO`` bank provider. Thanks cloveras.
* Add ``ipv4_network_class``, ``ipv4_private``, ``ipv4_public`` providers.
Thanks ZuluPro.
* Add ``address_class`` and ``private`` arguments to ``ipv4`` provider.
Thanks ZuluPro.
* Add ``currency``, ``currency_name``, ``cryptocurrency``,
``cryptocurrency_code`` and ``cryptocurrency_name`` to currency provider.
Thanks ZuluPro.
* Add automotive provider for ``de_DE``. Thanks gsilvan.
* Fix edgecases for Finnish ``ssn`` provider. Thanks sanga.
* Add job provider for ``pt_BR``. Thanks paladini.
* Add ``unix_device`` and ``unix_partition`` to ``file`` provider.
Thanks ZuluPro.
* Add ``random_lowercase_letter`` and ``random_uppercase_letter`` to the base
provider. Thanks ZuluPro.
* Clarify CLI help. Thanks confirmationbias616.