Update sphinx to 1.7.4

[pyup-bot]

This PR updates Sphinx from 1.7.3 to 1.7.4.

Changelog

1.7.4

=====================================

Bugs fixed
----------

* 4885, 4887: domains: Crashed with duplicated objects
* 4889: latex: sphinx.writers.latex causes recusrive import

Links

• PyPI: https://pypi.org/project/sphinx
• Changelog: https://pyup.io/changelogs/sphinx/
• Homepage: http://sphinx-doc.org/

[coveralls]

Pull Request Test Coverage Report for Build 74

• 0 of 0 (NaN%) changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 77.7%

---

Totals
Change from base Build 71:	0.0%
Covered Lines:	777
Relevant Lines:	1000

---

💛 - Coveralls