Live stream discovery!

@justinswart [wip] Remove Project.LiveStream (#63)
@mbrandonw Cleaned up a bunch of deprecation warnings (#64)
@justinswart Reduce memory leak overhead by replacing the current item with nil instead of only pausing it (#71)
@theginbin theginbin fix compose copy for dashboard updates
@justinswart justinswart Version OpenTok in Makefile (#73)
@justinswart Send subscribe toggle as form data, not JSON (#76)
@cdolm92 @mbrandonw Estimated delivery metadata (#72)
@kyeah Filter backings from recommended projects (#74)
@kyeah 🦐 Filter backings in discovery filter tests 🦐 (#79)
@mbrandonw [wip stretch goal] Live stream discovery (#53)
@cdolm92 Reward description truncation adjustment (#78)
@justinswart @mbrandonw Refresh live streams on project page appearing (#80)
@justinswart @mbrandonw Pause live video on disappear/reappear (#83)
@justinswart @mbrandonw Refreshing of the Live Stream Discovery view (#81)
@mbrandonw Set visitor cookie. (#82)
@theginbin Safe guard reward pledge shipping (#84)
@theginbin Swipe improvements (#70)
@mbrandonw Don't stream vid in discovery when not on wifi. (#86)
@justinswart @mbrandonw Live stream subscription state refresh (#77)
@justinswart @mbrandonw Add number of people watching to Discovery (#85)
@mbrandonw Make swiftlint error in circle when there are warnings (#87)
@mbrandonw Extract reward cell to its own nib (#88)
@mbrandonw Updated strings and screenshots. (#89)
@mbrandonw Add tracking to live discovery. (#91)