Test extras_require.

setup.py

@@ -1,29 +1,29 @@
 import setuptools
 
 with open("README.md", "r") as fh:
-    long_description = fh.read()
+	long_description = fh.read()
 
 with open('requirements_pypi.txt') as fp:
-    install_requires = fp.read()
+	install_requires = fp.read()
 
 setuptools.setup(
-    name="graphkit-learn",
-    version="0.2b3",
-    author="Linlin Jia",
-    author_email="linlin.jia@insa-rouen.fr",
-    description="A Python library for graph kernels, graph edit distances, and graph pre-images",
-    long_description=long_description,
-    long_description_content_type="text/markdown",
-    url="https://github.com/jajupmochi/graphkit-learn",
-    packages=setuptools.find_packages(),
-    classifiers=[
-        "Programming Language :: Python :: 3",
-        "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
-        "Operating System :: OS Independent",
-    ],
-    install_requires=install_requires,
+	name="graphkit-learn",
+	version="0.2b3",
+	author="Linlin Jia",
+	author_email="linlin.jia@insa-rouen.fr",
+	description="A Python library for graph kernels, graph edit distances, and graph pre-images",
+	long_description=long_description,
+	long_description_content_type="text/markdown",
+	url="https://github.com/jajupmochi/graphkit-learn",
+	packages=setuptools.find_packages(),
+	classifiers=[
+		"Programming Language :: Python :: 3",
+		"License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
+		"Operating System :: OS Independent",
+	],
+	install_requires=install_requires,
 	extras_require={
-        'control>=0.8.2': ['matplotlib>=3.1.0'], # for generalized random walk kernels only.
+		'control>=0.8.2': ['matplotlib>=3.1.0'], # for generalized random walk kernels only.
 		'control<0.8.2': ['matplotlib<3.1.0']
 		},
 )