added cython as a dependency for testing and developing

Author: maximtrp

pyproject.toml

@@ -65,6 +65,7 @@ dev = [
     "flake8>=4.0",
     "mypy>=0.950",
     "pre-commit>=2.15",
+    "cython>=0.29.0",
 ]
 docs = [
     "sphinx>=4.0",
@@ -75,6 +76,7 @@ docs = [
 test = [
     "pytest>=6.0",
     "pytest-cov>=2.10",
+    "cython>=0.29.0",
 ]
 benchmark = [
     "matplotlib>=3.3",