Prepare to publish (dart-lang/stream_transform#104)

pkgs/stream_transform/CHANGELOG.md

diff --git a/pkgs/stream_transform/CHANGELOG.md b/pkgs/stream_transform/CHANGELOG.md
index f235df1..f4cf395 100644
--- a/pkgs/stream_transform/CHANGELOG.md
+++ b/pkgs/stream_transform/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 1.2.0-dev
+## 1.2.0
 
 -  Add support for emitting the "leading" event in `debounce`.
 

pkgs/stream_transform/pubspec.yaml

diff --git a/pkgs/stream_transform/pubspec.yaml b/pkgs/stream_transform/pubspec.yaml
index c1d6298..c336b81 100644
--- a/pkgs/stream_transform/pubspec.yaml
+++ b/pkgs/stream_transform/pubspec.yaml
@@ -1,7 +1,7 @@
 name: stream_transform
 description: A collection of utilities to transform and manipulate streams.
 homepage: https://www.github.com/dart-lang/stream_transform
-version: 1.2.0-dev
+version: 1.2.0
 
 environment:
   sdk: ">=2.6.0 <3.0.0"