update gitignore; add tox and pre-commit config

.gitignore

@@ -1,8 +1,10 @@
-dist
-build
-.cache
-.coverage
-htmlcov
 *.egg-info
 *.pyc
 *.pyo
+.DS_Store
+.cache
+.coverage
+.eggs
+.tox
+build
+dist

.pre-commit-config.yaml

@@ -0,0 +1,9 @@
+repos:
+-   repo: https://github.com/ambv/black
+    rev: 21.12b0
+    hooks:
+    - id: black
+-   repo: https://github.com/asottile/reorder_python_imports
+    rev: v2.6.0
+    hooks:
+    - id: reorder-python-imports

pyproject.toml

@@ -0,0 +1,5 @@
+[build-system]
+requires = ["setuptools>=45", "wheel", "setuptools_scm[toml]>=6"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools_scm]

tox.ini

@@ -0,0 +1,21 @@
+[tox]
+minversion = 3
+envlist = py,build-dist
+isolated_build = True
+
+[testenv]
+commands = pytest {posargs:tests}
+deps =
+    lektor
+    pytest
+    pytest-cov
+    pytest-mock
+
+[testenv:build-dist]
+skip_install = True
+deps =
+    build
+    twine
+commands =
+    python -m build .
+    twine check dist/*