Merge pull request #1086 from adamtheturtle/pyup-update-sphinx-autodoc-typehints-1.8.0-to-1.9.0

Update sphinx-autodoc-typehints to 1.9.0

Author: adamtheturtle

dev-requirements.txt

@@ -21,7 +21,7 @@ pytest-cov==2.8.1  # Measure code coverage
 pytest==5.2.1  # Test runners
 PyYAML==5.1.2
 Sphinx==2.2.0
-sphinx-autodoc-typehints==1.8.0
+sphinx-autodoc-typehints==1.9.0
 sphinxcontrib-spelling==4.3.0
 twine==2.0.0
 versioneer==0.18