Pub: Implementing package spec proposal

[DartBot]

<img src="https://avatars.githubusercontent.com/u/5479?v=3" align="left" width="96" height="96"hspace="10"> Issue by sethladd
Originally opened as dart-lang/sdk#23370

---

Tracking issue for implementing the package spec proposal.

Main issue: dart-archive/dart_enhancement_proposals#5

Proposal: https://github.com/lrhn/dep-pkgspec/blob/master/DEP-pkgspec.md

[DartBot]

<img src="https://avatars.githubusercontent.com/u/5479?v=3" align="left" width="48" height="48"hspace="10"> Comment by sethladd

---

Marked this as blocking dart-lang/sdk#23372.

[DartBot]

<img src="https://avatars.githubusercontent.com/u/5479?v=3" align="left" width="48" height="48"hspace="10"> Comment by sethladd

---

cc @nex3.

[DartBot]

<img src="https://avatars.githubusercontent.com/u/5479?v=3" align="left" width="48" height="48"hspace="10"> Comment by sethladd

---

Set owner to @lrhn.
Added this to the 1.11 milestone.
Removed Priority-Unassigned label.
Added Priority-High label.

[DartBot]

<img src="https://avatars.githubusercontent.com/u/5479?v=3" align="left" width="48" height="48"hspace="10"> Comment by sethladd

---

the CL in progress: https://chromiumcodereview.appspot.com/1096723002/

[DartBot]

<img src="https://avatars.githubusercontent.com/u/5479?v=3" align="left" width="48" height="48"hspace="10"> Comment by sethladd

---

Added Started label.

[nex3]

This was fixed by 6a1d758.

[sethladd]

Great! Thanks for the update.