[doc] #202: Add contributing documenation

CONTRIBUTING.md

+doc/contributing.md
\ No newline at end of file

doc/contributing.md

+# Contributing
+
+## Goals
+Part of the Duniter project running the Ğ1 currency, Silkaj project is aiming to create a generic tool to manage his account and wallets, and to monitor the currency.
+
+## Install the development environement
+[Install Poetry.](install_poetry.md)
+This will install a sandboxed Python environement.
+Dependencies will be installed in it in order to have Silkaj running and to have pre-installed developement tools.
+
+## Workflow
+- We use branches for merge requests
+- We prefer fast-forward and rebase method than having a merge commit. This in order to have a clean history.
+
+## Branches
+- `master` branch as stable
+- maintainance branches, to maintain a stable version while developing future version with breaking changes: `0.7`
+- `dev` branch
+
+## Develop in DuniterPy
+[DuniterPy](https://git.duniter.org/clients/python/duniterpy) is a Python library for Duniter clients.
+It implements a client with multiple APIs, the handling for document signing.
+It is very coupled with Silkaj, so we oftenly need to develop in both repositories.
+
+### How to use DuniterPy as editable with Poetry
+Clone DuniterPy locally alongside of `silkaj` repository:
+
+```bash
+git clone https://git.duniter.org/clients/python/duniterpy
+```
+
+Use DuniterPy as a [path dependency](https://poetry.eustace.io/docs/versions/#path-dependencies):
+```bash
+poetry add duniter --path ../duniterpy
+poetry install --develop duniterpy
+```
+
+In `pyproject.toml`, you can also comment and uncomment DuniterPy lines, then run `poetry install`.
+
+## Formatting
+We are using [Black](https://github.com/python/black) as a formatter.
+
+Black is not in the development dependencies in order to keep Python 3.5 support.
+There is three way you can install Black:
+- From your package manager. i.e. Debian Buster: `sudo apt install black`
+- On your machine with `pip`: `pip3 install black --user`
+- In your Poetry virtualenv:
+To have it installed in your Poetry virtualenv, you need Python v3.6 or greater.
+In the `pyproject.toml` pass the Python requirement version from "3.5.x" to "3.6".
+Then, install it with `poetry add black --dev`.
+
+Once installed in your development environement, go in the development environement:
+```bash
+poetry shell
+```
+
+Run Black on a Python file to format it:
+```bash
+black silkaj/cli.py
+```
+
+### Pre-commit
+Then, you can use `pre-commit` tool to check staged changes before committing.
+To do so, you need to call `pre-commit install` to install the git hook.
+Black is called on staged files, so commits should fail if black made changes.
+You will have to add changes made by Black to commit your changes.
+
+## Tests
+We are using [Pytest](https://pytest.org) tests framework.
+
+Read the [test documentation](test_and_coverage.md).
+
+To run tests, still within Poetry shell and in `silkaj` repository:
+```bash
+pytest
+```
+
+### How to run a single test
+Specifiy the path of the test:
+```bash
+pytest tests/test_end_to_end.py
+```
+
+## Version update
+We are using the [Semantic Versioning](https://semver.org).
+
+To create a release, we use following script which will update the version in different files, and will make a commit and a tag out of it.
+```bash
+./release.sh 0.8.1
+```
+
+Then, a `git push --tags` is necessary to publish the tag. Git could be configured to publish tags with a simple `push`.
+
+## PyPi and PyPi test distributions
+Silkaj is distributed to PyPi, the Python Package Index, for further `pip` installation.
+Silkaj can be published to [PyPi](https://pypi.org/project/silkaj) or to [PyPi test](https://test.pypi.org/project/silkaj/) for testing purposes.
+Publishing to PyPi or PyPi test can be directly done from the continuous delivery or from Poetry it-self.
+The CD jobs does appear on a tag and have to be triggered manually.
+Only the project maintainers have the rights to publish tags.
+
+### PyPi
+Publishing to PyPi from Poetry:
+```bash
+poetry publish --build
+```
+### PyPi test
+Publishing to PyPi test from Poetry:
+```bash
+poetry config repositories.pypi_test https://test.pypi.org/legacy/
+poetry publish --build --repository pypi_test
+```
+
+To install this package:
+```bash
+pip install --index-url https://test.pypi.org/simple/ --extra-index-url https://pypi.python.org/simple/ silkaj
+```
+
+The `--extra-index-url` is used to retrieve dependencies packages from the official PiPy not to get issues with missing or testing dependencies comming PyPi test.
+
+## Continuous integration and delivery
+### Own built Docker images
+- https://git.duniter.org/docker/python3/poetry
+- Python images based on Debian Stretch and Buster
+- Poetry installed on top
+- Black installed on v3.8
+
+### Jobs
+- Checks:
+  - Format
+  - Build:
+- Tests on supported Python versions:
+  - Installation
+  - Pytest for v3.5, 3.6, 3.7, and 3.8
+- PyPi distribution
+  - test
+  - stable