Fixes #769.

Fixes #771

The options hash passed to Facter::Core::Execution.execute expect a
`time_limit`, not a `limit`:
https://www.rubydoc.info/gems/facter/Facter/Core/Execution#execute-class_method

When this fact was evaluated, an exception was raised:
Error: Facter: Error while resolving custom fact fact='docker_worker_join_token', resolution='<anonymous>': private method `execute' called for Facter::Util::Resolution:Class

Switch from Facter::Util::Resolution to Facter::Core::Execution and set
a time limit of 90s to match the rest of the file.

This make it easier to debug failing unit tests.

Fix facts gathering

Facter 4 documentation and code was inconsistent regarding naming of
this option.  `limit` and `time_limit` have been replaced by `timeout`
which also match the option name in previous versions of facter.  The
old names will output a warning when used, so swith to the new
terminology now.

Releated PR:
puppetlabs/facter#2429

…debian_8_support

pdksync - (IAC-1598) - Remove Support for Debian 8

Prefer timeout to time_limit for Facter::Core::Execution

Release prep v4.1.2