Bump yarl from 1.6.3 to 1.7.0 (#101)

Bumps [yarl](https://github.com/aio-libs/yarl) from 1.6.3 to 1.7.0.
- [Release notes](https://github.com/aio-libs/yarl/releases)
- [Changelog](https://github.com/aio-libs/yarl/blob/master/CHANGES.rst)
- [Commits](aio-libs/yarl@v1.6.3...v1.7.0)

---
updated-dependencies:
- dependency-name: yarl
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements/base.txt

@@ -11,4 +11,4 @@ frozenlist==1.1.1
 gunicorn==20.1.0
 typing_extensions==3.7.4.3
 uvloop==0.14.0; platform_system!="Windows" and implementation_name=="cpython" and python_version<"3.9" # MagicStack/uvloop#14
-yarl==1.6.3
+yarl==1.7.0