Extract `Feed.initialize_from_uri` to parse and initialize feed.
Merge pull request #84 from onk/extract_initialize_from_uri_method

Extract `Feed.initialize_from_uri` to parse and initialize feed.
Move XML generation logic to view using builder.
Fix missing date order
Add a content type for opml
Change a content type of opml
Add spec for user controller
Merge branch 'spike/refactor-user-controller' of github.com:aerith/fastladder into refactor-user-controller