Bump aiohttp from 3.7.2 to 3.7.3 in /packages/service-library

Bumps [aiohttp](https://github.com/aio-libs/aiohttp) from 3.7.2 to 3.7.3.
- [Release notes](https://github.com/aio-libs/aiohttp/releases)
- [Changelog](https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst)
- [Commits](aio-libs/aiohttp@v3.7.2...v3.7.3)

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

packages/service-library/requirements/_base.txt

@@ -5,16 +5,13 @@
 #    pip-compile --output-file=requirements/_base.txt requirements/_base.in
 #
 aiodebug==1.1.2           # via -r requirements/_base.in
-aiohttp==3.7.2            # via -r requirements/_base.in, aiozipkin
+aiohttp==3.7.3            # via -r requirements/_base.in, aiozipkin
 aiopg[sa]==1.0.0          # via -r requirements/_base.in
 aiozipkin==0.7.1          # via -r requirements/_base.in
 async-timeout==3.0.1      # via aiohttp
 attrs==20.3.0             # via -r requirements/_base.in, aiohttp, jsonschema, openapi-core
 chardet==3.0.4            # via aiohttp
-dataclasses==0.7          # via pydantic
-idna-ssl==1.1.0           # via aiohttp
-idna==2.10                # via idna-ssl, yarl
-importlib-metadata==3.0.0  # via jsonschema
+idna==2.10                # via yarl
 isodate==0.6.0            # via openapi-core
 jsonschema==3.2.0         # via -r requirements/_base.in, openapi-spec-validator
 lazy-object-proxy==1.4.3  # via -r requirements/_base.in, openapi-core
@@ -31,11 +28,10 @@ sqlalchemy[postgresql_psycopg2binary]==1.3.19  # via -r requirements/_base.in, a
 strict-rfc3339==0.7       # via openapi-core
 tenacity==6.2.0           # via -r requirements/_base.in
 trafaret==2.1.0           # via -r requirements/_base.in
-typing-extensions==3.7.4.3  # via aiohttp, yarl
+typing-extensions==3.7.4.3  # via aiohttp
 ujson==4.0.1              # via -r requirements/_base.in
 werkzeug==1.0.1           # via -r requirements/_base.in
 yarl==1.5.1               # via aiohttp
-zipp==3.4.0               # via importlib-metadata
 
 # The following packages are considered to be unsafe in a requirements file:
 # setuptools

packages/service-library/requirements/_test.txt

@@ -4,7 +4,7 @@
 #
 #    pip-compile --output-file=requirements/_test.txt requirements/_test.in
 #
-aiohttp==3.7.2            # via -c requirements/_base.txt, pytest-aiohttp
+aiohttp==3.7.3            # via -c requirements/_base.txt, pytest-aiohttp
 astroid==2.4.2            # via pylint
 async-timeout==3.0.1      # via -c requirements/_base.txt, aiohttp
 attrs==20.3.0             # via -c requirements/_base.txt, aiohttp, jsonschema, pytest, pytest-docker
@@ -21,9 +21,7 @@ docker-compose==1.27.4    # via pytest-docker
 docker[ssh]==4.3.1        # via docker-compose
 dockerpty==0.4.1          # via docker-compose
 docopt==0.6.2             # via coveralls, docker-compose
-idna-ssl==1.1.0           # via -c requirements/_base.txt, aiohttp
-idna==2.10                # via -c requirements/_base.txt, idna-ssl, requests, yarl
-importlib-metadata==3.0.0  # via -c requirements/_base.txt, jsonschema, pluggy, pytest
+idna==2.10                # via -c requirements/_base.txt, requests, yarl
 iniconfig==1.1.1          # via pytest
 isort==5.6.4              # via pylint
 jsonschema==3.2.0         # via -c requirements/_base.txt, docker-compose
@@ -54,13 +52,11 @@ six==1.15.0               # via -c requirements/_base.txt, astroid, bcrypt, cryp
 termcolor==1.1.0          # via pytest-sugar
 texttable==1.6.3          # via docker-compose
 toml==0.10.2              # via pylint, pytest
-typed-ast==1.4.1          # via astroid
-typing-extensions==3.7.4.3  # via -c requirements/_base.txt, aiohttp, yarl
+typing-extensions==3.7.4.3  # via -c requirements/_base.txt, aiohttp
 urllib3==1.26.2           # via requests
 websocket-client==0.57.0  # via docker, docker-compose
 wrapt==1.12.1             # via astroid
 yarl==1.5.1               # via -c requirements/_base.txt, aiohttp
-zipp==3.4.0               # via -c requirements/_base.txt, importlib-metadata
 
 # The following packages are considered to be unsafe in a requirements file:
 # setuptools