Fix #49: google-signin-offline is not fired
Merge pull request #50 from plequang/issue-49-offline-event

Fix #49: google-signin-offline is not fired
Update dependencies to 0.4.x

Polymer
Google APIs
Core signals
Paper Focusable
Ripples

with resolutions to work with other Polymer elements.
Reorganise the element notes.

Also add a note on local testing.
Bump to 0.1.0

Per semver: MINOR version when you add functionality in a
backwards-compatible manner.