Bump sphinx from 1.7.6 to 1.7.7

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 1.7.6 to 1.7.7.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v1.7.6...v1.7.7)

Signed-off-by: dependabot[bot] <support@dependabot.com>

pyproject.lock

@@ -644,7 +644,7 @@ name = "sphinx"
 optional = false
 platform = "any"
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
-version = "1.7.6"
+version = "1.7.7"
 
 [package.dependencies]
 Jinja2 = ">=2.3"
@@ -822,7 +822,7 @@ requests = ["63b52e3c866428a224f97cab011de738c36aec0185aa91cfacd418b5d58911d1",
 restructuredtext-lint = ["c48ca9a84c312b262809f041fe47dcfaedc9ee4879b3e1f9532f745c182b4037"]
 six = ["70e8a77beed4562e7f14fe23a786b54f6296e34344c23bc42f07b15018ff98e9", "832dc0e10feb1aa2c68dcc57dbb658f1c7e65b9b61af69048abc87a2db00a0eb"]
 snowballstemmer = ["919f26a68b2c17a7634da993d91339e288964f93c274f1343e3bbbe2096e1128", "9f3bcd3c401c3e862ec0ebe6d2c069ebc012ce142cce209c098ccb5b09136e89"]
-sphinx = ["217ad9ece2156ed9f8af12b5d2c82a499ddf2c70a33c5f81864a08d8c67b9efc", "a765c6db1e5b62aae857697cd4402a5c1a315a7b0854bbcd0fc8cdc524da5896"]
+sphinx = ["71531900af3f68625a29c4e00381bee8f85255219a3d500a3e255076a45b735e", "a3defde5e17b5bc2aa21820674409287acc4d56bf8d009213d275e4b9d0d490d"]
 sphinx-autodoc-typehints = ["1a9df6cb3ba72453ea4bfbe96ea887abc0d796b2ce9508c2189217a1bb69b366", "46cc9e985ee6d8bbbd07fffd95b815c39a72df6afb600f59671f85f7340e7d0d"]
 sphinx-readable-theme = ["f5fe65a2e112cb956b366df41e0fc894ff6b6f0e4a4814fcbff692566db47fc0"]
 sphinxcontrib-napoleon = ["614b779888629f14dfdfad6c17bffbb6d3813a0a0917a9541651d85384d4d6bd", "cbb31953b15d2102c18f16f02591f92e2614a08ef0218c9e514e2dc4c4f9daf9"]