Fix typo in setup.py (#746)

This PR fixes typo I made `extras_requires` -> `extras_require`

Authors:
  - GALI PREM SAGAR (https://github.com/galipremsagar)

Approvers:
  - Keith Kraus (https://github.com/kkraus14)

URL: #746

python/setup.py

@@ -206,7 +206,7 @@ def get_cuda_version_from_header(cuda_include_dir):
     ],
     # Include the separately-compiled shared library
     setup_requires=["Cython>=0.29,<0.30"],
-    extras_requires={"test": ["pytest", "pytest-xdist"]},
+    extras_require={"test": ["pytest", "pytest-xdist"]},
     ext_modules=extensions,
     packages=find_packages(include=["rmm", "rmm.*"]),
     package_data=dict.fromkeys(