update list of supported OS
@@ -18,7 +18,7 @@ Requirements
.. note::
- Currently, CuPy is tested against `Ubuntu <https://www.ubuntu.com/>`_ 18.04 LTS (x86_64), `CentOS <https://www.centos.org/>`_ 7 (x86_64) and Windows Server 2016 (x86_64).
+ Currently, CuPy is tested against `Ubuntu <https://www.ubuntu.com/>`_ 18.04 LTS / 20.04 LTS (x86_64), `CentOS <https://www.centos.org/>`_ 7 / 8 (x86_64) and Windows Server 2016 (x86_64).
Python Dependencies
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