[Release] Bumped datadog_checks_base version to 11.11.1

[florimondmanca]

What does this PR do?

11.11.1 / 2020-06-17

• [Fixed] Gracefully skip quantile-less summary metrics. See #6909.

Motivation

To be included in next bug fix release / custom beta build.

Additional Notes

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[codecov]

Codecov Report

Merging #6915 into master will increase coverage by 0.54%.
The diff coverage is 100.00%.

Impacted Files	Coverage Δ
...tadog_checks_base/datadog_checks/base/__about__.py	100.00% <100.00%> (ø)
disk/tests/common.py	64.28% <0.00%> (-35.72%)	⬇️
disk/tests/conftest.py	85.71% <0.00%> (-11.43%)	⬇️
disk/datadog_checks/disk/disk.py	83.66% <0.00%> (-3.59%)	⬇️
disk/tests/test_filter.py	96.45% <0.00%> (-3.55%)	⬇️
dns_check/datadog_checks/dns_check/dns_check.py	86.45% <0.00%> (-2.09%)	⬇️
couch/datadog_checks/couch/couch.py	87.83% <0.00%> (-1.53%)	⬇️
etcd/tests/test_integration.py	97.43% <0.00%> (-0.86%)	⬇️
mcache/datadog_checks/mcache/mcache.py
openstack/datadog_checks/openstack/openstack.py
... and 405 more