removes empty assets files

fixes 'new' button in admin

hopefully improves the user account page UI where the omniauth logins are listed. Need to test on heroku so i get a callback from facebook
Truncate OAuth key and secret in list view

OAuth keys and secrets can be really long (i.e. with Google's OAuth 2). This causes the list of authentication methods to grow too big horizontally. Truncating the keys solves this issue.

Fixes #73
Log instead of print loading of authentication source

Which authentications sources get loaded during initialization is informational and should be logged as such - and not written to stdout.
Run 1-3-stable through travis as well
Updates to make code decoupled from devise.
Fix user references to spree_user.
Fix remaining references to :user noticed by @swrobel.
Attempt fallback to social authentication for user.
Merge pull request #78 from supherman/url_helper

Use url helper instead of raw url generated based on the site_url spree ...
Bump to Spree 2.0 final.
Change how password required is called & setup selenium.
Use Spree.t in _user_form.
Use Spree.t for i18n.
Use Spree.t instead of t helper
Use Spree.t instead of t helper
Merge pull request #86 from wuboy0307/patch-1

Use Spree.t instead of t helper
Merge pull request #87 from wuboy0307/patch-2

Use Spree.t instead of t helper