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-preview[bot] <support@dependabot.com>

requirements/dev.txt

@@ -4,24 +4,42 @@
 #
 #    pip-compile --output-file=requirements/dev.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==5.3.1           # via pytest-cov
-iniconfig==1.1.1          # via pytest
-mock==4.0.3               # via -r requirements/dev.in
-packaging==20.8           # via pytest
-pip-tools==5.4.0          # via -r requirements/dev.in
-pluggy==0.13.1            # via pytest
-py==1.10.0                 # via pytest
-pylibmc==1.6.1; platform_system != 'Windows'            # via -r requirements/dev.in
-pyparsing==2.4.7          # via packaging
-pytest-cov==2.10.1        # via -r requirements/dev.in
-pytest==6.2.1             # via -r requirements/dev.in, pytest-cov
-python-memcached==1.59    # via -r requirements/dev.in
-six==1.15.0               # via pip-tools, python-memcached
-toml==0.10.2              # via pytest
+attrs==20.3.0
+    # via pytest
+click==7.1.2
+    # via pip-tools
+coverage==5.3.1
+    # via pytest-cov
+iniconfig==1.1.1
+    # via pytest
+mock==4.0.3
+    # via -r requirements/dev.in
+packaging==20.8
+    # via pytest
+pip-tools==5.4.0
+    # via -r requirements/dev.in
+pluggy==0.13.1
+    # via pytest
+py==1.10.0
+    # via pytest
+pylibmc==1.6.1
+    # via -r requirements/dev.in
+pyparsing==2.4.7
+    # via packaging
+pytest-cov==2.11.1
+    # via -r requirements/dev.in
+pytest==6.2.1
+    # via
+    #   -r requirements/dev.in
+    #   pytest-cov
+python-memcached==1.59
+    # via -r requirements/dev.in
+six==1.15.0
+    # via
+    #   pip-tools
+    #   python-memcached
+toml==0.10.2
+    # via pytest
 
 # The following packages are considered to be unsafe in a requirements file:
 # pip