Replace setup.py with pyproject.toml configured to use flit for builds (#2940)

* Add pyproject.toml file

* Remove setup.py and MANIFEST.in files

* Make dev version string follow PEP440

Author: mwaskom

MANIFEST.in

@@ -0,0 +1,43 @@
+[build-system]
+requires = ["flit_core >=3.2,<4"]
+build-backend = "flit_core.buildapi"
+
+[project]
+name = "seaborn"
+description = "Statistical data visualization"
+authors = [{name = "Michael Waskom", email = "[email protected]"}]
+readme = "README.md"
+license = {file = "LICENSE.md"}
+dynamic = ["version"]
+classifiers = [
+    "Intended Audience :: Science/Research",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "License :: OSI Approved :: BSD License",
+    "Topic :: Scientific/Engineering :: Visualization",
+    "Topic :: Multimedia :: Graphics",
+    "Operating System :: OS Independent",
+    "Framework :: Matplotlib",
+]
+requires-python = ">=3.7"
+dependencies = [
+    "numpy>=1.17",
+    "pandas>=0.25",
+    "matplotlib>=3.1",
+    "typing_extensions; python_version < '3.8'",
+]
+
+[project.optional-dependencies]
+stats = [
+    "scipy>=1.3",
+    "statsmodels>=0.10",
+]
+
+[project.urls]
+Source = "https://github.com/mwaskom/seaborn"
+Docs = "http://seaborn.pydata.org"
+
+[tool.flit.sdist]
+exclude = ["doc/_static/*.svg"]

pyproject.toml

@@ -18,4 +18,4 @@
 _orig_rc_params = mpl.rcParams.copy()
 
 # Define the seaborn version
-__version__ = "0.12.0dev0"
+__version__ = "0.12.0.dev0"