Bump rspec-rails dependency to 2.12.0
Removes useless call to order#update!

The only reason I could see for those to be there is to make a test
pass. But the problem was on the test itself due to the way stubs work.
Also add some doc blocks to CreateAdjustment class.
Remove CSV references from core.rake

These tasks do not support CSV files
Add 1.8.7 support back to Travis
Bump Rails to 3.2.11
[api] Convert 1.9 hash syntax to hashrocket syntax within inventory_units
controller

Fixes #2398

Fixes #2400
Bumping Rails Version in README to 3.2.11
Freeze to rspec-rails 2.12.0 due to this commit:

https://github.com/rspec/rspec-rails/commit/09793f885637ee4d6f5cc2c10b4f60b078acb9b5#commitcomment-2403679
[promo] Fix 1.8 syntax error in promotions/actions/create_adjustment_spec
Fix autocomplete issue in customer details with latest jquery UI

Fixes #2408
Fix issue where single quotes would break taxonomies/get_children response

Fixes #2413
Ensure option values in Variant#options_text are sorted in a predictable order

Fixes #2432
Show TravisCI badge for 1-2-stable branch