[enh] #162: Introduce isort dep and pre-commit hook

Use black profile:
https://github.com/PyCQA/isort/issues/1518#issuecomment-703056188
https://pycqa.github.io/isort/docs/configuration/config_files/
https://pycqa.github.io/isort/docs/configuration/profiles/

.pre-commit-config.yaml

@@ -3,6 +3,11 @@ repos:
     rev: 21.5b0
     hooks:
     - id: black
+-   repo: https://github.com/PyCQA/isort
+    rev: 5.8.0
+    hooks:
+    - id: isort
+      args: ["--profile", "black"]
 -   repo: https://github.com/pre-commit/mirrors-mypy
     rev: v0.812
     hooks:

pyproject.toml

@@ -37,7 +37,12 @@ websocket-client = "^0.57"
 [tool.poetry.dev-dependencies]
 black = {version = "^21.4b2", allow-prereleases = true}
 mypy = "^0.790"
+isort = "^5.8.0"
 pylint = "^2.7.2"
 pre-commit = "^2.12.1"
 sphinx = "^3.2.1"
 sphinx_rtd_theme = "^0.5.0"
+
+[tool.isort]
+profile = "black"
+src_paths = ["duniterpy", "tests", "examples"]