Add .travis.yml

The script is going to build `master` with `gulp` on every push and, if
successful, push the resulting `dist/` to `gh-pages`.

.travis.yml

+# You must sign into travis-ci.org and set the commit hook on your project for travis to
+# run on your project. The secure: variable must be generated by running `travis encrypt`
+# on a github oauth key that you can generate using curl.
+
+language:
+    node_js
+node_js:
+    - 0.10
+notifications:
+    irc: "irc.freenode.org#tastejs"
+branches:
+    only:
+        - master
+env:
+    global:
+        # GH_OAUTH_TOKEN is the oauth token generated as described at
+        # https://help.github.com/articles/creating-an-oauth-token-for-command-line-use
+        #
+        # curl -u 'username' -d '{"scopes":["repo"],"note":"push to gh-pages from travis"}' https://api.github.com/authorizations
+        #
+        # It must be encrypted using the travis gem
+        # http://about.travis-ci.org/docs/user/build-configuration/#Secure-environment-variables
+        #
+        # travis encrypt GH_OAUTH_TOKEN=XXXXXXXXXXXXXXX
+        #
+        # User specific env variables
+        - secure: "fHgfjMpYuliwMr2QLnjYZExIViNrxprf9dhXRBLZ6P9Hz7P6m1BMYrI/xEG8X+fFbCi0+n3AXh8SEMHi9ou/Pty/cx12z4w/z3B2BHMxh4XBwpZHs+AB4IXkLiwwWoP4QFy4vTipgYnMDMq9CRhlRbhZEpenQBmaTEc472By1uM="
+        - GH_OWNER: tastejs
+        - GH_PROJECT_NAME: todomvc
+
+before_script:
+    # install dependencies
+    - npm install -g gulp
+script:
+    # We want to gate on passing tests and a successful build
+    - gulp
+after_success:
+    # Any command that using GH_OAUTH_TOKEN must pipe the output to /dev/null to not expose your oauth token
+    - git submodule add -b gh-pages https://${GH_OAUTH_TOKEN}@github.com/${GH_OWNER}/${GH_PROJECT_NAME} site > /dev/null 2>&1
+    - cd site
+    - if git checkout gh-pages; then git checkout -b gh-pages; fi
+    - git rm -r .
+    - cp -R ../dist/* .
+    - cp ../dist/.* .
+    - git add -f .
+    - git config user.email "travis@rdrei.net"
+    - git config user.name "TasteBot"
+    - git commit -am "update the build files for gh-pages [ci skip]"
+    # Any command that using GH_OAUTH_TOKEN must pipe the output to /dev/null to not expose your oauth token
+    - git push https://${GH_OAUTH_TOKEN}@github.com/${GH_OWNER}/${GH_PROJECT_NAME} HEAD:gh-pages > /dev/null 2>&1