Bump pub version

Includes the following changes:
a4bc2dd08630f85a94f506eab037fcaaedb42222 Rename --v2 to --dart-dev-run (#2498)
958862efa33605af3136c4bd366015bace62d869 Update outdated.dart (#2488)
2cc09730f73204afced1df606416c07d5ee1e67d outdated: work with no lock file (#2491)
7c73dae26df2b3ef3e3019d7296fd2871dd23c49 Do not fallback to bin/main.dart (#2478)
27bc4f7ef65928c95535baf51245fd5b01162d0f Preserve windows line endings in pubspec.lock if they are already there (#2489)
31cfec521db6fe607f0f0424e747dff2e4950711 pub outdated --mode=null-safety
da05bbaee8c53b769d1f90458e28b3b7f9a22187 Fix `pub run` precompilation with relative PUB_CACHE paths (#2486)
dd005e586fc17545f22fc6e75eedfc9f075f9092 Show summary count of outdated packages after running `pub upgrade`  (#2444)
1b927956e653ea74a153513e593ff417617cabf0 Outdated: If current is a prerelease, use prereleases for latest if no newer stable (#2484)
678bd84a328fabb3fee360f837ac782f2831d753 Warn first time a package version opts in to null-safety (#2465)
8e76d46a4b8180ab247ecf6382f4f7abd34591f1 Force colors when --color is given (#2481)
572a23f815a5d632a8c2b259b691792674cd8b4d Rely on terminal telling if we can use colors (#2475)
363ed6fe54c084df43bbec1704757d0d6c64cbb7 pub run --v2 for use in dartdev (#2435)
aa5bbbb7261fc492866b5d6b94357cbe8df5e09a Use a 8-bit ansi palette for grey (#2474)
3929b1138a589b4f506018d98b3005a3e76dcea6 Format with new dartfmt (#2476)
6deb457048deb435009b36a4cd2d86003d107cf4 Use line length to wrap usage (#2457)
6e2ce2e4add80c4e15c8346a976cbf760d707f6a Use gzip decoder from dart:io. (#2382)
5b5fe72a33a66e4cab7070b3248596877e3a854e Improve the `pub outdated --help` text (#2429)

Change-Id: If9a719bfc374f085bd26856330547682c14f0df4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/148532
Reviewed-by: Jonas Jensen <[email protected]>
Commit-Queue: Jonas Jensen <[email protected]>

Author: sigurdm

CHANGELOG.md

@@ -73,6 +73,19 @@ Updated the Linter to `0.1.115`, which includes:
 
 ### Dart VM
 
+### Pub
+* Introduce `pub outdated --mode=null-safety` that will report which of your
+  dependencies you can upgrade to fully support null safety.
+* Fix `pub run` precompilation with relative `PUB_CACHE` paths (#2486)
+* Warn at publishing first time a package version opts in to null-safety.
+* Preserve Windows line endings in pubspec.lock if they are already there (#2489)
+* Better terminal color-detection. Use colors in terminals on Windows.
+* `pub outdated`: If the current version of a dependency is a prerelease 
+  version, use prereleases for latest if no newer stable.
+* `pub outdated` now works without a lockfile. In that case the 'Current'
+  column will be empty.
+* `pub upgrade`: Show summary count of outdated packages after running.
+
 ## 2.8.2 - 2020-05-13
 
 This is a patch release that fixes an AOT compilation bug in global

DEPS

@@ -121,7 +121,7 @@ vars = {
   "ply_rev": "604b32590ffad5cbb82e4afef1d305512d06ae93",
   "pool_tag": "86fbb2cde9bbc66c8d159909d2f65a5981ea5b50",
   "protobuf_rev": "3746c8fd3f2b0147623a8e3db89c3ff4330de760",
-  "pub_rev": "3606265962da4248d34d352aa3d170aae4496a90",
+  "pub_rev": "a4bc2dd08630f85a94f506eab037fcaaedb42222",
   "pub_semver_tag": "v1.4.4",
   "quiver-dart_tag": "2.0.0+1",
   "resource_rev": "f8e37558a1c4f54550aa463b88a6a831e3e33cd6",