Roll Observatory packages and add a roll script

packages/usage/tool/travis.sh

+#!/bin/bash
+
+# Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+# Fast fail the script on failures.
+set -e
+
+# Verify that the libraries are error free.
+dartanalyzer --fatal-warnings \
+  lib/usage.dart \
+  lib/usage_html.dart \
+  lib/usage_io.dart \
+  test/all.dart
+
+# Run the tests.
+dart test/all.dart
+
+# Run the UI/web tests as well.
+pub build test
+pub run grinder:test build/test/web.html
+
+# Measure the size of the compiled JS, for the dart:html version of the library.
+dart tool/grind.dart build
+
+# Install dart_coveralls; gather and send coverage data.
+if [ "$REPO_TOKEN" ]; then
+  pub global activate dart_coveralls
+  pub global run dart_coveralls report \
+    --token $REPO_TOKEN \
+    --retry 2 \
+    --exclude-test-files \
+    test/all.dart
+fi