Upgrade sidekiq to v3.x
Merge pull request #562 from neighborly/jl-upgrade-sidekiq

Upgrade sidekiq to v3.x
Remove unnecessary nil

Empty returns already means `return nil`.
Remove rescue which unexpectedly skips a failed block

Project::VideoHandler#download_video_thumbnail is called just from
workers, not directly affecting the user. If, for some reason the
thumbnail download fail, it used to happen silently. Without it, will
throw an exception and queued to retry list.
Refactor rewards controller to not use inherited_resources
Does not let project be updated with thumbnails of invalid video urls
Remove unused action for render video info in json
Remove contributions query from project box
Merge pull request #563 from neighborly/jl-rewards-refact

Refactor rewards controller to not use inherited_resources
Protect Project::VideoHandler#video method
Create placeholder image to show when thumbnail upload is in progress
Merge pull request #565 from neighborly/jl-remove-contributions-query-on-project-box

Remove contributions query from project box
Configure AWS region using env vars
Remove host and endpoint from CarrierWave configuration
Configure asset_sync to serve assets from S3
Merge pull request #567 from neighborly/jl-cdn

Configure asset_sync to serve assets from S3
Set aws region as amazon's default
Merge pull request #564 from neighborly/im-remove-rescue-nil

Remove witchcraft of getting video thumbnail while not downloaded yet
Remove aws region config
Let's delete existing files from assets pipeline