addFromURL fails to follow redirections

[maxlath]

ipfs.util.addFromURL('http://covers.openlibrary.org/book/id/969165.jpg')

will return the hash of an empty file (QmbFMke1KXqnYyBBWxB74N4c5SBnJMVAiMNRcGu6x1AwQH instead of the expected QmaL9zy7YUfvWmtD5ZXp42buP7P4xmZJWFkm78p8FJqgjg) because request.js doesn't follow redirections

[maxlath]

@diasdavid would it be acceptable to introduce a new dependency such as follow-redirects to solve this issue?

[daviddias]

@maxlath looks promising! My first question was to make sure to check the deps it would bring and the increase in bundle size, but after skimming through follow-redirects, it seems it is the most compact solution we could use :) Move ahead! Thank you.

[daviddias]

Work happening at #514