Updating sample to comply with Swagger v2

[cikasfm]

I had to spend quite some time to figure out what was wrong with my code. Apparently, the sample had a deprecated property definition, now should bedefinitions

[kalinchernev]

Hi @cikasfm thanks for this pull request, using definition should still be a working scenario for you, could you please check which version are you using? In v1.8.1 both singular and plural forms should be acceptable and the singular should yield a warning of future deprecation. Could you verify that please?
I have no issues merging this, just wondering if you have latest version and would be notified for future deprecation as intended.

[cikasfm]

Hi @kalinchernev! Yes, it does work using definition but keeps printing a deprecation warning. It took me quite a while to figure out why this is happening ( up to debugging your code... :) for whatever reason I didn't 'see' this earlier... ) so when I understood that the problem was in the sample I thought it would make sense to update the sample itself.

I actually was using v1.8.1 at the time of writing.

[kalinchernev]

@cikasfm I see ... thanks! :)
PS And sorry for the trouble you had to debug this!

[cikasfm]

Sure, you're welcome!