Bump outcome from 1.0.1 to 1.1.0 (#236)

Bumps [outcome](https://github.com/python-trio/outcome) from 1.0.1 to 1.1.0.
- [Release notes](https://github.com/python-trio/outcome/releases)
- [Commits](python-trio/outcome@v1.0.1...v1.1.0)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

requirements.txt

@@ -10,5 +10,5 @@ six==1.15.0
 tornado==5.1.1; python_version<"3.6"
 tornado==6.0.4; python_version>="3.6"
 trio==0.16.0; python_version>="3.6"
-outcome==1.0.1; python_version>="3.5"
+outcome==1.1.0; python_version>="3.5"
 attrs==19.3.0; python_version>="3.5"