Ensure bytes for ssl connection

[AlexandreYang]

What does this PR do?

Ensure bytes for ssl connection

Motivation

The integration is broken for Python 3 when TLS is used:

2020-06-19 09:17:13 UTC | CORE | WARN | (pkg/collector/python/datadog_agent.go:119 in LogMessage) | ibm_mq:9d243cc47a1f6817 | (ibm_mq.py:44) | cannot connect to queue manager: Python 3 style string (unicode) found but not allowed here: TLS_RSA_WITH_AES_256_CBC_SHA256. Convert to bytes.

Additional Notes

This is a quick fix with simple unit test. I plan to add a e2e test for ssl, but will take more time.

[codecov]

Codecov Report

Merging #6913 into master will increase coverage by 2.32%.
The diff coverage is 100.00%.

Impacted Files	Coverage Δ
ibm_mq/datadog_checks/ibm_mq/connection.py	83.78% <100.00%> (+21.62%)	⬆️
ibm_mq/tests/test_ibm_mq_unit.py	100.00% <100.00%> (ø)
cisco_aci/datadog_checks/cisco_aci/capacity.py
...node/datadog_checks/hdfs_namenode/hdfs_namenode.py
druid/datadog_checks/druid/__init__.py
openmetrics/datadog_checks/openmetrics/__init__.py
...g_checks_base/datadog_checks/base/stubs/similar.py
...adog_checks/cloud_foundry_api/cloud_foundry_api.py
crio/datadog_checks/crio/__about__.py
external_dns/tests/test_external_dns.py
... and 830 more

[florimondmanca]

Nice catch, some questions :-)