Bump caypbara to 2.1.0:

* Add timeout into config/database.yml template to avoid SQLite3 DB locked out
* Use lenient non-exact setting for Capybara element matcher (same as 1.x)
Capybara 2 updates.
Fix Frontend specs for capybara2.
Fix backend specs for Capybara 2.
Add .ruby-version to gitignore.
Fix API specs for Capybara 2 on Ruby 1.9.3.
Dont use database_cleaner when Ruby 2.0+
DatabaseCleaner is not required for Core specs.
Create partials for every section of admin layout

Help users and extensions to customize those sections more easily
Sets stock locations backorderable_default to false and stock item backorderable to false. Fixes #3300
Remove unused Order#checkout_allowed? method
[sample] Provide feedback when loading images

This can take a long time due to Paperclip doing its thing for all the different image styles.

Fixes #3395