Roll versions and add a new release_notes directory.

TBR=johhmccutchan@google.com

Review URL: https://codereview.chromium.org/1231413004 .

sdk/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.0.18
+
+  - 41 changes: https://github.com/domokit/mojo/compare/246e279...c3119f6
+
 ## 0.0.17
 
   - 18 changes: https://github.com/domokit/mojo/compare/e7433cf...8879bfd

sdk/example/demo_launcher/apk/AndroidManifest.xml

@@ -3,7 +3,7 @@
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file.
  -->
-<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="org.domokit.sky.demo" android:versionCode="17" android:versionName="0.0.17">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="org.domokit.sky.demo" android:versionCode="18" android:versionName="0.0.18">
 
     <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="21" />
     <uses-permission android:name="android.permission.INTERNET" />

sdk/example/demo_launcher/apk/release_notes/0.0.18.txt

@@ -0,0 +1 @@
+First version published to production from our service account.

sdk/pubspec.yaml

@@ -1,14 +1,14 @@
 author: Chromium Authors <sky-dev@googlegroups.com>
 dependencies:
-  cassowary: '^0.1.7'
-  mojo_services: '^0.0.15'
-  mojo: '^0.0.17'
-  mojom: '^0.0.17'
-  newton: '^0.1.0'
-  vector_math: '^1.4.3'
+  cassowary: ^0.1.7
+  mojo: ^0.0.17
+  mojo_services: ^0.0.15
+  mojom: ^0.0.17
+  newton: ^0.1.0
+  vector_math: ^1.4.3
 description: Dart files to support executing inside Sky.
-homepage: https://github.com/domokit/mojo/tree/master/sky
 environment:
-  sdk: ">=1.8.0 <2.0.0"
+  sdk: '>=1.8.0 <2.0.0'
+homepage: https://github.com/domokit/mojo/tree/master/sky
 name: sky
-version: 0.0.17
+version: 0.0.18