prep the release for 2.10 dev sdk (#147)

This is in preparation for the actual 2.10 dev sdk release. This package needs to be published and pinned in flutter simultaneously with that release.
diff --git a/.travis.yml b/.travis.yml
index 5801d68..2b8d5af 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,33 +1,33 @@
 language: dart
 
 dart:
-- dev
+- preview/raw/2.10.0-0.2-dev
 
 jobs:
   include:
     - stage: analyze_and_format
       name: "Analyze lib/"
-      dart: dev
+      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: dartanalyzer --fatal-warnings --fatal-infos lib/
     - stage: analyze_and_format
       name: "Analyze test/"
-      dart: dev
+      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: dartanalyzer --enable-experiment=non-nullable --fatal-warnings --fatal-infos test/
     - stage: analyze_and_format
       name: "Format"
-      dart: dev
+      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: dartfmt -n --set-exit-if-changed .
     - stage: test
       name: "Vm Tests"
-      dart: dev
+      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: pub run --enable-experiment=non-nullable test -p vm 
     - stage: test
       name: "Web Tests"
-      dart: dev
+      dart: preview/raw/2.10.0-0.2-dev
       os: linux
       script: pub run --enable-experiment=non-nullable test -p chrome
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 93b4bf9..6e3a846 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.15.0-nullsafety.2
+
+Update for the 2.10 dev sdk.
+
 ## 1.15.0-nullsafety.1
 
 * Allow the <=2.9.10 stable sdks.
diff --git a/pubspec.yaml b/pubspec.yaml
index 9569802..500c527 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,11 +1,11 @@
 name: collection
-version: 1.15.0-nullsafety.1
+version: 1.15.0-nullsafety.2
 
 description: Collections and utilities functions and classes related to collections.
 homepage: https://www.github.com/dart-lang/collection
 
 environment:
-  sdk: '>=2.9.0-20.0 <=2.9.10'
+  sdk: '>=2.10.0-0 <2.10.0'
 
 dev_dependencies:
   pedantic: ^1.0.0