GC-45: Update copyright information:

- Changes to code base were previously done in 2020 as well (based on
git history).

GC-37: Update status command to include relevant/correct information about ECDSA algorithms:

- Updated functional test to include case where CA hierarchy has been
initialised with the ECDSA keys.
- Updated unit tests to include testing of output for entities that
use ECDSA keys.
- Use the key_specification_from_public_key function to obtain
information about key in use (instead of assuming it's RSA).

GC-37: Added support for showing key algorithms to the status command:

- Updated functional test for the status command to include a variety
of key algorithms and to test for their representation in the
output.
- Added unit tests.
- Updated the status command to extract key algorithm information from
the issued certificates and output the information.

GC-22: Updated status command to display path to CSR if certificate was issued using CSR:

- Updated the existing functional test for validating output from the
status command on an initialised directory.
- Updated status command to check for existence or private key or CSR,
and display appropriate message and path to it.
- Updated unit tests covering the status command output.

GC-20: Implemented status command for initialised directory:

- Added functional test.
- Implemented showing CA hierarchy, server and client certificate
information for initialised directories.
- Implemented helper functions for generating string representation of
DNs, DNS subject alternative names, and date range.
- Return correct error when calling status command on uninitialised
directory.
- Updated gitignore to exclude *.pyc from repository.
- Implemented unit tests.

GC-20: Show informative message when calling status command on uninitialised directory:

- Added small function test to cover the scenario when status command
is called on an uninitalised directory.
- Updated the status command implementation.
- Implemented the necessary unit tests.

GC-20: Added initial dummy implementation of status command:

- Added functional test checking if the command is available and has
help.
- Updated unit tests for new CLI command.
- The command does not do anything at the moment.