Ignore `pkg` directory and built gems from git
Remove duplicated spec helper
Prepare Yard settings and fix warning
Remove ResourceLocking namespace pollution

`Fog::ResourceLocking` is not relevant to any code outside of the
Brightbox compute code so it should not have been defined so high up.
Add master fog style rubocop config
Autocorrect styling issues
Fix indentation issues
Fix "for" shadowing outer `key`
Fix indentation style report

It looks worse but then raising conditional errors from a case was never
going to end pretty.
Fix occurrence of unless/else
Update documentation