Added IMDB back in by allowing users to add in their omdbapi key

[ro-savage]

OMDBAPI is now free for people who register for 1000 req a day.

Could we add the feature back in, and in the config allow people to enter the own API key?

Alternatively, if this project is still backed by LifeHacker for $1 a month you get 100,000 reqs per day which might cover all the users of this project.