Update cx_oracle to 7.2.1

[pyup-bot]

This PR updates cx_Oracle from 6.2.1 to 7.2.1.

Changelog

7.2.1

-------------------------

)  Resolved ``MemoryError`` exception on Windows when using an output type
 handler
 (`issue 330 <https://github.com/oracle/python-cx_Oracle/issues/330>`__).
)  Improved test suite and samples.
)  Improved documentation.

7.2

-----------------------

7.1.3

--------------------------

7.1.2

--------------------------

7.1.1

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7.1

---------------------------

7.0

----------------------------

6.4.1

-------------------------

6.4

-----------------------

6.3.1

------------------------

6.3

------------------------

Links

• PyPI: https://pypi.org/project/cx-oracle
• Changelog: https://pyup.io/changelogs/cx-oracle/
• Repo: https://oracle.github.io/python-cx_Oracle

[pyup-bot]

Closing this in favor of #71