Add twitter handle to profile

[jaredbeck]

As a visitor,
I want to see the twitter handles of gem owners,
because I want to follow them on twitter

I can try to implement this if it's something people want.

[lucianosousa]

Firstly, we should allow at gemspec file this info, don't?

[ghost]

Yes, possibly an optional extra field. I for instance do not have a twitter handler but I can see that others may want to know more about some gem owners.

[dwradcliffe]

👍 I think this is a good idea. Sometimes it's hard to find someone just based on their RubyGems.org username. This would (optionally) be on the RubyGems.org user profile, not on the gem or gemspec.

[LoChanHi5]

I would like to work on this if nobody has started yet. It'll be my first open-source contribution 😄

[sonalkr132]

This was implemented in #1361. Users can go to https://rubygems.org/profile/edit to add their twitter handle.