Add 'setup_fixtures' configuration option
Add 'setup_fixtures' configuration option

When using a modulepath that already satisfies the correct structure,
the call to `RSpec::Puppet::Setup.safe_setup_directories` emits the
'Unable to determine module name.' error message despite the specs
continuing to run correctly.

This adds a configuration option to disable the default fixtures setup.

DavidS/rspec-puppet,puppetlabs/rspec-puppet,rodjek/rspec-puppet