Update movie retrieval logic

[frank-tan]

Currently the app retrieve 60 movies by popularity and 60 movies by vote average within last 6 months. The app do the retrieval every 24 hours with 4 hours flexible time. It upsert db record but do not delete any records.

http://api.themoviedb.org/3/discover/movie?api_key=xxx&sort_by=popularity.desc&page=1&primary_release_date.gte=2015-02-20

and

http://api.themoviedb.org/3/discover/movie?api_key=xxx&sort_by=vote_average.desc&page=1&primary_release_date.gte=2015-02-20

The alternative better solution might be calling

GET https://api.themoviedb.org/3/movie/popular?api_key=xxx

or

GET https://api.themoviedb.org/3/movie/top_rated?api_key=xxx

or

GET https://api.themoviedb.org/3/movie/now_playing?api_key=xxx