Bump aiomcache from 0.8.0 to 0.8.1

Bumps [aiomcache](https://github.com/aio-libs/aiomcache) from 0.8.0 to 0.8.1.
- [Release notes](https://github.com/aio-libs/aiomcache/releases)
- [Changelog](https://github.com/aio-libs/aiomcache/blob/master/CHANGES.rst)
- [Commits](aio-libs/aiomcache@v0.8.0...v0.8.1)

---
updated-dependencies:
- dependency-name: aiomcache
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

setup.py

@@ -121,7 +121,7 @@ def readme():
     extras_require = {
         "memcache": [
             "pylibmc==1.6.3",
-            "aiomcache==0.8.0",
+            "aiomcache==0.8.1",
         ],
         "gdrive": [
             'PyDrive==1.3.1',
@@ -155,7 +155,7 @@ def readme():
             'python-logstash-async==2.5.0',
             'aiologstash==2.0.0',
             'PyYAML>=6.0',
-            "aiomcache==0.8.0",
+            "aiomcache==0.8.1",
         ]
     },
     ext_modules=cythonize(extensions),