Bump aiohttp from 3.6.2 to 3.8.1

Bumps [aiohttp](https://github.com/aio-libs/aiohttp) from 3.6.2 to 3.8.1.
- [Release notes](https://github.com/aio-libs/aiohttp/releases)
- [Changelog](https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst)
- [Commits](https://github.com/aio-libs/aiohttp/compare/v3.6.2...v3.8.1)

---
updated-dependencies:
- dependency-name: aiohttp
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,19 +1,29 @@
-aiohttp==3.6.2
+#
+# These requirements were autogenerated by pipenv
+# To regenerate from the project's Pipfile, run:
+#
+#    pipenv lock --requirements
+#
+
+-i https://pypi.python.org/simple/
 aiohttp-jinja2==1.2.0
-async-timeout==3.0.1
+aiohttp==3.8.1
+aiosignal==1.2.0; python_full_version >= '3.6.0'
+async-timeout==4.0.2; python_full_version >= '3.6.0'
 atomicwrites==1.3.0
-attrs==19.3.0
-chardet==3.0.4
+attrs==21.4.0; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'
+charset-normalizer==2.1.0; python_full_version >= '3.6.0'
 docopt==0.6.2
+frozenlist==1.3.0; python_version >= '3.7'
 hbmqtt==0.9.5
-idna==2.8
-Jinja2==2.10.3
-MarkupSafe==1.1.1
+idna==3.3; python_version >= '3.5'
+jinja2==2.10.3
+markupsafe==2.1.1; python_version >= '3.7'
 multidict==4.5.2
-passlib==1.7.2
-PyYAML==5.3b1
-six==1.13.0
+passlib==1.7.4
+pyyaml==5.3b1
+six==1.16.0; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3'
 tinydb==3.15.2
-transitions==0.7.1
-websockets==8.1
+transitions==0.8.11
+websockets==10.3; python_version >= '3.7'
 yarl==1.3.0