Fix logging with --no-colors outputting objects

The issue here was that when logging from Attester with `--no-colors`
passed in command line, it sometimes logged the String object (console.dir
fashion) instead of a logging a string literal (precisely it was fixed by
https://github.com/Marak/colors.js/commit/5ca667df4a9f86f6c202eca5eb1524cd8d2dd331).

Close #48.
Fix missing console logs from TestCampaign constructor

After refactoring attester as a module, logger is attached too late for
the logs from campaign constructor to be displayed in the console (because
"attester.start" is raised after the initial campaigns creation).

This adds a new event "attester.config.available" which is raised at the
very beginning, before campaign creation, so we can set up the logging
early.

Close #51.
Update links after ownership transfer

Attester now has its own organization, not anymore part of ariatemplates
Expose main module script

To use attester as a module it's necessary to specify a `main` file in the package.json
Use xml2js instead of xml2json (test dependency).

This removes dependencies on external compilation tools.
xml2js is written in pure JavaScript whereas xml2json
relies on node-expat which is a native module requiring
compilation.