"busser plugin install" doesn't respect system gemrc

[aespinosa]

I'm not sure if it should respect that or it should be in another entry in .kitchen.yml. But here's the difference of the two:

• gem install - https://github.com/rubygems/rubygems/blob/master/lib/rubygems/commands/install_command.rb#L22-L28
• busser plugin install - https://github.com/test-kitchen/busser/blob/master/lib/busser/rubygems.rb#L76-L78

This difference might explain what I mentioned earlier in #18

[damacus]

Closing due to inactivity.

If this is still an issue please reopen or open another issue.

Thanks, Test-Kitchen Maintainers