Bump py from 1.9.0 to 1.10.0 in /requirements

Bumps [py](https://github.com/pytest-dev/py) from 1.9.0 to 1.10.0.
- [Release notes](https://github.com/pytest-dev/py/releases)
- [Changelog](https://github.com/pytest-dev/py/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/py@1.9.0...1.10.0)

---
updated-dependencies:
- dependency-name: py
  dependency-type: direct:development
...

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

requirements/dev-py36.txt

@@ -58,7 +58,7 @@ pre-commit==2.7.1         # via -r requirements/dev.in
 prompt-toolkit==3.0.7     # via ipython
 psycopg2-binary==2.8.6    # via -r requirements/dev.in, small-small-hr
 ptyprocess==0.6.0         # via pexpect
-py==1.9.0                 # via tox
+py==1.10.0                 # via tox
 pycodestyle==2.6.0        # via -r requirements/dev.in, autopep8, flake8
 pydocstyle==5.1.1         # via -r requirements/dev.in
 pyflakes==2.2.0           # via flake8

requirements/dev-py37.txt

@@ -56,7 +56,7 @@ pre-commit==2.7.1         # via -r requirements/dev.in
 prompt-toolkit==3.0.7     # via ipython
 psycopg2-binary==2.8.6    # via -r requirements/dev.in, small-small-hr
 ptyprocess==0.6.0         # via pexpect
-py==1.9.0                 # via tox
+py==1.10.0                 # via tox
 pycodestyle==2.6.0        # via -r requirements/dev.in, autopep8, flake8
 pydocstyle==5.1.1         # via -r requirements/dev.in
 pyflakes==2.2.0           # via flake8

requirements/dev-py38.txt

@@ -55,7 +55,7 @@ pre-commit==2.7.1         # via -r requirements/dev.in
 prompt-toolkit==3.0.7     # via ipython
 psycopg2-binary==2.8.6    # via -r requirements/dev.in, small-small-hr
 ptyprocess==0.6.0         # via pexpect
-py==1.9.0                 # via tox
+py==1.10.0                 # via tox
 pycodestyle==2.6.0        # via -r requirements/dev.in, autopep8, flake8
 pydocstyle==5.1.1         # via -r requirements/dev.in
 pyflakes==2.2.0           # via flake8