Update dependencies

Author: Cito

poetry.lock

@@ -29,15 +29,15 @@ packages = [
 python = "^3.6"
 
 [tool.poetry.dev-dependencies]
-pytest = "^4.4"
+pytest = "^4.6"
 pytest-asyncio = "^0.10"
-pytest-cov = "^2.6"
+pytest-cov = "^2.7"
 pytest-describe = "^0.12"
-pyyaml = "^5.0"
+pyyaml = "^5.1"
 black = "^19.3b0"
 flake8 = "^3.7"
 mypy = "^0.701"
-tox = "^3.9"
+tox = "^3.12"
 codecov = "^2.0"
 sphinx = "^2.0"
 sphinx_rtd_theme = "^0.4"