claat: bump version number to 0.7.1

claat: version bump

render: add Google Analytics and async js src

claat, render: support of an "offline" out format

The offline output creates a set of files, each per step,
to support a codelab consumption directly from an offline storage, such
as a USB thumbdrive.

claat: bump version to v0.5.1

claat: bump version to 0.5.0

claat: use crc64 checksum for image filenames

This will de-dup and reduce number of image copies on disc.

parser/gdoc: stricter metadata/title parsing

Recognize metadata table and title only until the first step is found.

misc: update CI image to Go 1.6.2

Bump version to v0.3.0