Add pygisceclient CLI for scripting and AI agent use

[Copilot]

Adds a command-line interface to the package so ERP methods can be called from shell scripts and AI agent skills without writing Python.

Changes

• gisce/cli.py — argparse-based CLI; connects via the existing connect() function, calls a model method, and prints the result as JSON to stdout. Errors go to stderr with a non-zero exit code.
• setup.py — registers pygisceclient as a console_scripts entry point.
• tests/test_cli.py — 18 tests covering argument parsing, auth variants, JSON validation, error paths, and successful calls.
• README.md — CLI usage section with options table and examples.

Usage

# Search with user/password auth
pygisceclient \
  --url https+xmlrpc://erp.example.com \
  --database mydb \
  --user admin --password secret \
  --model res.users \
  --method search \
  --args '[[["active", "=", true]]]'

# Read specific fields with a token
pygisceclient \
  --url https+restapi://erp.example.com \
  --database mydb \
  --token myapitoken \
  --model res.users \
  --method read \
  --args '[[1, 2, 3]]' \
  --kwargs '{"fields": ["name", "login"]}'

Result is printed as indented JSON to stdout, making it straightforward to pipe into jq or consume in agent tool calls.

[ecarreras]

@copilot arregla els tests per python2

Run pytest tests/ -v --tb=short
============================= test session starts ==============================
platform linux2 -- Python 2.7.18, pytest-4.6.11, py-1.11.0, pluggy-0.13.1 -- /usr/local/bin/python
cachedir: .pytest_cache
rootdir: /__w/py-gisce-client/py-gisce-client
collecting ... collected 8 items / 1 errors / 7 selected

==================================== ERRORS ====================================
______________________ ERROR collecting tests/test_cli.py ______________________
ImportError while importing test module '/__w/py-gisce-client/py-gisce-client/tests/test_cli.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
tests/test_cli.py:7: in <module>
    from unittest.mock import patch, MagicMock
E   ImportError: No module named mock
=============================== warnings summary ===============================
/usr/local/lib/python2.7/site-packages/responses/__init__.py:85
  /usr/local/lib/python2.7/site-packages/responses/__init__.py:85: DeprecationWarning: Support for Python 2.7 is being removed from the next release of responses. Pin your dependency to responses==0.17 or lower.
    DeprecationWarning,

-- Docs: https://docs.pytest.org/en/latest/warnings.html
!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!!
===================== 1 warnings, 1 error in 0.23 seconds ======================

[Copilot]

@copilot arregla els tests per python2

...

Fixed in a6b8129. Changed the mock import to use the same Python 2/3 compatible pattern as the existing tests:

try:
    from unittest.mock import patch, MagicMock
except ImportError:
    from mock import patch, MagicMock

Also added mock to requirements-dev.txt so it's available on Python 2.7.