Rails 4.2 Types namespace moved

This pull request addresses following failure since https://github.com/rails/rails/commit/728fa69839d2c3b839391f9077896c06df80bddf has been merged to rails.

```ruby
$ rspec ./spec/active_record/connection_adapters/oracle_enhanced_connection_spec.rb:228
Run options: include {:locations=>{"./spec/active_record/connection_adapters/oracle_enhanced_connection_spec.rb"=>[228]}}
F

Failures:

  1) OracleEnhancedConnection SQL with bind parameters when NLS_NUMERIC_CHARACTERS is set to ', ' should execute prepared statement with decimal bind parameter
     Failure/Error: column = ActiveRecord::ConnectionAdapters::OracleEnhancedColumn.new('age', nil, ActiveRecord::ConnectionAdapters::Type::Decimal.new, 'NUMBER(10,2)')
     NameError:
       uninitialized constant ActiveRecord::ConnectionAdapters::Type
     # ./spec/active_record/connection_adapters/oracle_enhanced_connection_spec.rb:230:in `block (3 levels) in <top (required)>'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/extensions/instance_eval_with_args.rb:16:in `instance_exec'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/extensions/instance_eval_with_args.rb:16:in `instance_eval_with_args'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example.rb:116:in `block in run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example.rb:248:in `with_around_each_hooks'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example.rb:113:in `run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example_group.rb:515:in `block in run_examples'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example_group.rb:511:in `map'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example_group.rb:511:in `run_examples'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example_group.rb:496:in `run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example_group.rb:497:in `block in run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example_group.rb:497:in `map'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/example_group.rb:497:in `run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/command_line.rb:24:in `block (2 levels) in run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/command_line.rb:24:in `map'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/command_line.rb:24:in `block in run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/reporter.rb:58:in `report'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/command_line.rb:21:in `run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/runner.rb:103:in `run'
     # /home/yahonda/.rvm/gems/ruby-2.1.2@rails42/gems/rspec-core-2.99.2/lib/rspec/core/runner.rb:17:in `block in autorun'

Finished in 0.09045 seconds
1 example, 1 failure

Failed examples:

rspec ./spec/active_record/connection_adapters/oracle_enhanced_connection_spec.rb:228 # OracleEnhancedConnection SQL with bind parameters when NLS_NUMERIC_CHARACTERS is set to ', ' should execute prepared statement with decimal bind parameter
$
```