unixPB: Install Python2.7 on C6; Use it to install JDKs

[Willsparker]

Fixes: #1877

IT WORKS! (in VPC at least: https://ci.adoptopenjdk.net/job/VagrantPlaybookCheck/1067/ )

Installs Python 2.7 on CentOS6 and then uses that Python to run the adoptopenjdk_install tasks. See the referenced issue for what other things were tried or suggested. This solution also adds some future proofing somewhat, in that we can just use the Python2.7 whenever we have another unarchive / get_url cert issue because CentOS6 is old.

Checklist

• commit message has one of the standard prefixes
• FAQ.md updated if appropriate
• other documentation is changed or added (if applicable)
• playbook changes run through VPC or QPC (if you have access) : See above
• for inventory.yml changes, bastillion/nagios/jenkins updated accordingly

[sxa]

How long does this role to execute? Could be preferable to use the pre-built one I put in place last week instead which would also avoid having to install the extra prereq packages on the machine.

[karianna]

Fix YAMLLint please :-)

[Willsparker]

How long does this role to execute? Could be preferable to use the pre-built one I put in place last week instead which would also avoid having to install the extra prereq packages on the machine.

About 10 minutes in VPC , not sure on the GHCheck as it doesn't have timestamps. But yeah, okay, I'll try prebuilt :-)

[Willsparker]

Well it works! 🎉