Add tests_require to setup.py

Document test dependencies. pytest-pycharm is optional, but I like it.

setup.py

@@ -9,6 +9,7 @@ setup(
     author='nyanpasu64',
     author_email='',
     description='',
+    tests_require=['pytest', 'pytest-pycharm', 'hypothesis'],
     install_requires=['numpy', 'scipy', 'imageio', 'click', 'matplotlib',
                       'dataclasses;python_version<"3.7"', 'ruamel.yaml']
 )