Increase sequence table performance.
Restore default ENGINE to InnoDB.
Get current id with dummy update sql. because select can't work under massive update.
Merge pull request #8 from hanabokuro/increase-sequence-table-performance

Increase sequence table performance.
Bump version to 1.1.2
Drop support ruby-1.9.2
Add Ruby 2.1.1 to travis target
Fix wrong ruby version: 2.1.0 -> 2.1.1
add setting for rails 4.0.0
exclude: ruby 1.9.2 & rails 4.0.0

[because]
Installing activesupport (4.0.0)
Gem::InstallError: activesupport requires Ruby version >= 1.9.3.
An error occurred while installing activesupport (4.0.0), and Bundler cannot
can run test
Upgrade AR and AS
2.0.0.beta
Update README
Remove deprecation warnings
Follow ConnectionHandler changes.
Follow ActiveRecord::Persistence changes.
Fix when connection adapters returns ActiveRecord::Result
Add before blocks
Remove Rails 3.x settings on travis