v0.4.0

Changelog

• de7b628: Add momentums_stalled and pillar_missed rules (@0x3639)
• e39ae67: Add pillar alerts spec and plan (@0x3639)
• 955a613: Add pillar lookup to the node client (@0x3639)
• e5e1995: Document pillar alerts; roadmap item 2 done (@0x3639)
• b649501: Merge pull request #3 from 0x3639/pillar-alerts (@0x3639)
• 7de6c2a: Show pillar production in status and top (@0x3639)
• 5d1b731: Wire the pillar name through setup, daemon, status and top (@0x3639)
• 64b595a: pillar_missed: require a full window after an epoch rollover (@0x3639)