Update the vision from five to four points and add a mission.
Inspired by https://medium.com/@barmstrong/the-vision-mission-and-strategy-for-coinbase-944b79a64a7c#.8fqd0b9nk
/cc @AshleyS
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Inspired by https://medium.com/@barmstrong/the-vision-mission-and-strategy-for-coinbase-944b79a64a7c#.8fqd0b9nk
/cc @AshleyS