Bump pytest-cov from 2.10.1 to 2.11.1 (#83)

* Bump pytest-cov from 2.10.1 to 2.11.1

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 2.10.1 to 2.11.1.
- [Release notes](https://github.com/pytest-dev/pytest-cov/releases)
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v2.10.1...v2.11.1)

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

* rm poetry.lock

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Shota Imaki <shota.imaki.0801@gmail.com>

pyproject.toml

@@ -13,7 +13,7 @@ requests = "^2.23.0"
 
 [tool.poetry.dev-dependencies]
 pytest = "^6.1.2"
-pytest-cov = "^2.10.1"
+pytest-cov = "^2.11.1"
 codecov = "^2.1.10"
 flake8 = "^3.9.0"
 black = "^20.8b1"