travis: migrated to dart_task and added dart2js testing (firefox) (#25)

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index 9dfa8c3..c2842f8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,25 @@
 language: dart
-script: ./tool/travis.sh
-env:
-  - DARTANALYZER_FLAGS=--fatal-warnings
+sudo: false
+
+dart:
+ - dev
+ - stable
+
+dart_task:
+ - test: --platform vm
+   xvfb: false
+ - test: --platform firefox -j 1
+ - dartanalyzer --fatal-warnings
+
+matrix:
+  include:
+  - dart: stable
+    dart_task: dartfmt
+
+# Only building master means that we don't run two builds for each pull request.
+branches:
+  only: [master]
+
+cache:
+  directories:
+    - $HOME/.pub-cache

tool/travis.sh

diff --git a/tool/travis.sh b/tool/travis.sh
deleted file mode 100755
index b7cc146..0000000
--- a/tool/travis.sh
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/bin/bash
-
-# Copyright (c) 2015, 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 and warning-free.
-echo "Running dartanalyzer..."
-dartanalyzer lib/fixnum.dart test/all_tests.dart
-
-# Run the tests.
-echo "Running tests..."
-dart -c test/all_tests.dart
-
-# Gather and send coverage data.
-if [ "$REPO_TOKEN" ]; then
-  echo "Collecting coverage..."
-  pub global activate dart_coveralls
-  pub global run dart_coveralls report \
-    --token $REPO_TOKEN \
-    --retry 2 \
-    --exclude-test-files \
-    test/all_tests.dart
-fi