bosun report attention

User story: I am a project manager. I want a report of all invalid tickets, so that I can correct them.

Suggested solution: The following invocation should generate a simple HTML report

bosun report attention https://source.puri.sm/liberty
# generates liberty_attention.html in current folder

See #1 (moved) for implementation details

---

Needs attention report for <Name> group

Milestone 1

Milestone description. Due 2019-13-13.

Phase	Path	Title	Effort	Priority	Due
On hold	example#3	Example t...	High	Low	2019-13-13

Milestone 2

Milestone description. Due 2019-13-13.

Phase	Path	Title	Effort	Priority	Due
On hold	example#3	Example t...	High	Low	2019-13-13

...

No milestone

Phase	Path	Title	Effort	Priority	Due
On hold	example#3	Example t...	High	Low	2019-13-13

Section logic:
Group by MILESTONE
Order groups by MILESTONE.DUE_DATE, MILESTONE.TITLE
In each group:
Select all OPEN TICKETS in MILESTONE where PHASE in (On hold, Please review, To deploy, Invalid)
Order by PHASE, PATH