add bundler cache.
Merge pull request #6 from wata-gh/add_bundler_cache

add bundler cache.
Update README.md
first create by generator-gulp-angular
set up sass command.
bundle install --path vendor/bundle
set up bower and install

npm install bower --save-dev
./node_modules/.bin/bower install
setup bower task before wiredep.
add readme memo.
rename dir sap to spa
adjust tab to white space.
unit and e2e test check done.
init coffee-script setting.
rewrite build.js
rewrite bower.js
rewrite e2e-tests.js
rewrite proxy.js
rewrite server.js
rewrite  unit-tests.js
rewrite watch.js
rewrite wiredep.js
rewrite gulpfile.js