[DB MIGRATION REQ'D] Store Facebook profile updated time

Get updated_time from facebook and store in tu_instances_facebook.profile_update
Adds instances_facebook table.
Adds FacebookInstanceMySQLDAO.
Adds FacebookInstance.
Adds lots of tests.
Updates crawler to store the updated_time for a given running instance.
Ignore Grunt and NPM files and config
[DB MIGRATION REQ'D] Add user gender and age fields
This commit is only the database migration which adds gender and age fields to the users table.
Laying the groundwork for future insights related to gender and age.
Fix rollback markup
[DB MIGRATION REQ'D] Added tu_user_versions table, DAO, tests

Support version history of user data over time
[DB MIGRATION REQ'D] Become trial-aware
Update README.md

Fix links to Facebook Platform PHP5 SDK and ReCAPTCHA PHP library.

Old: https://github.com/facebook/php-sdk -> 404
New: https://github.com/facebook/facebook-php-sdk -> Works!
> Note: https://github.com/facebook/facebook-php-sdk-v4 is the latest version.

Old: http://recaptcha.net/plugins/php/ -> 404
New: https://developers.google.com/recaptcha/docs/php -> Works!
> Note: http://recaptcha.net/ redirects to https://developers.google.com/recaptcha/
Merge pull request #2089 from therobinkim/patch-1

Update README.md