Bump pytest from 6.1.2 to 6.2.1

Bumps [pytest](https://github.com/pytest-dev/pytest) from 6.1.2 to 6.2.1.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@6.1.2...6.2.1)

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

requirements/dev.txt

@@ -4,10 +4,8 @@
 #
 #    pip-compile --output-file=requirements/dev-py3.txt requirements/dev.in
 #
-atomicwrites==1.4.0       # via pytest
 attrs==20.3.0             # via pytest
 click==7.1.2              # via pip-tools
-colorama==0.4.4           # via pytest
 coverage==5.3             # via pytest-cov
 iniconfig==1.1.1          # via pytest
 mock==4.0.2               # via -r requirements/dev.in
@@ -17,7 +15,7 @@ pluggy==0.13.1            # via pytest
 py==1.9.0                 # via pytest
 pyparsing==2.4.7          # via packaging
 pytest-cov==2.10.1        # via -r requirements/dev.in
-pytest==6.1.2             # via -r requirements/dev.in, pytest-cov
+pytest==6.2.1             # via -r requirements/dev.in, pytest-cov
 six==1.15.0               # via packaging, pip-tools
 toml==0.10.2              # via pytest