update pub for latest changes

Bug:
Change-Id: I67d3ade64561f8623df4fc6ab488e33bac2db480
Reviewed-on: https://dart-review.googlesource.com/3281
Reviewed-by: Kevin Moore <kevmoo@google.com>
Reviewed-by: Bob Nystrom <rnystrom@google.com>

CHANGELOG.md

@@ -72,6 +72,33 @@
   * Removed require.js module loading timeout for dartdevc, which resolves an
     issue where the initial load of an app might give a timeout error.
 
+  * There is now a default SDK constraint of `<2.0.0` for any package with
+    no existing upper bound. This allows us to move more safely to 2.0.0.
+
+  * All new packages published on pub will now require an upper bound SDK
+    constraint so future major releases of Dart don't destabilize the package
+    ecosystem.
+
+  * When on a pre-release SDK build, all upper bounds matching exactly the
+    current SDK version but with no pre-release or build modifier will be
+    upgraded to be <= the current SDK version. This allows early adopters to
+    try out packages that don't explicitly declare support yet. You can disable
+    this functionality by setting the PUB_ALLOW_PRERELEASE_SDK system
+    environment variable to `false`.
+
+  * Added `--executables` option to `pub deps` command. This will list all
+    available executables that can be run with `pub run`.
+
+  * Fixed https://github.com/dart-lang/pub/issues/1684 so root package analysis
+    options are not enforced for dependencies when compiling with dartdevc.
+
+  * Fixed https://github.com/dart-lang/sdk/issues/30246 so you can include dart
+    scripts from subdirectories with dartdevc.
+
+  * Added a PUB_MAX_WORKERS_PER_TASK system environment variable which can be
+    set to configure the number of dartdevc/analyzer workers that are used
+    when compiling with --web-compiler=dartdevc.
+
 * dartfmt
 
     * Support assert in const constructor initializer lists.

DEPS

@@ -107,7 +107,7 @@ vars = {
   "ply_rev": "@604b32590ffad5cbb82e4afef1d305512d06ae93",
   "pool_tag": "@1.3.0",
   "protobuf_tag": "@0.5.4",
-  "pub_rev": "@0f122625f8e607842afe156b9b23a9709e4ce39a",
+  "pub_rev": "@cde958f157d3662bf968bcbed05580d5c0355e89",
   "pub_semver_tag": "@1.3.2",
   "quiver_tag": "@0.22.0",
   "resource_rev":"@a49101ba2deb29c728acba6fb86000a8f730f4b1",