Add Twitter Card support

[chayev]

Using a website reference, check if that website has proper Twitter Card support. This would allow you to confirm that your site will display properly when shared on Twitter.

Use case: yurl twittercard validate <location>

Alias: tc

Output:

• Valid - return whether the Twitter Card data format is valid (based on Reference)
• Invalid - return whether the Twitter Card data format is invalid based on above reference
• Not Found - tags not found

[FelicianoTech]

@chayev You want me to take this one?

[chayev]

@FelicianoTech yes. Let me know if there are any questions as you work through it.