adds a model for Orders requests

[ColinW520]

Resolves #100

• adds an Order model with list and create operations.
• adds a basic spec

I followed existing patterns for the spec; but, would like to see additional context testing for confidence sake. Example:

context 'given valid parameters' do
  it 'returns an Order object' do
  end
en

context 'given invalid/incomplete parameters' do
  it 'returns an Error object' do
  end
end

[jfriedr]

Thanks for digging into this. I'll look into what we can do about this context testing and get back to you.

Do you mind sharing what version of ruby you're using?

[ColinW520]

Thanks @jfriedr! I'm presently on ruby 2.6.6.

Happy to help if needed.

[jfriedr]

@ColinW520 apologies for the delay. I needed to take some time off and am still playing a bit of catch up. If you put in a pull request our team can do a quick review and then go through the steps of pushing it to the gems.org repo.