Merge pull request #135 from mceachen/ci_support

Make Travis test against ActiveRecord 3.2, 4.0, and 4.1
Preserve passed options in drop_table

`extract_options!` is a destructive method - the `super` call doesn’t
get the extracted options.
Merge pull request #138 from tmikoss/master

Preserve passed options in drop_table
Remove leading spaces in code examples

There were redundant leading spaces in code examples. Let's remove them.
Merge pull request #144 from gmile/patch-1

Remove leading spaces in code examples
Merge remote-tracking branch 'hug/master'