Update library

 * rspec to 3.1.0
 * guard-rspec to 4.5.0
 * rb-fsevent to 0.9.4
 * terminal-notifier-guard to 1.6.4
Convert specs to RSpec 3.1.0 syntax with Transpec

This conversion is done by Transpec 2.3.7 with the following command:
    transpec --convert example_group

* 28 conversions
    from: shared_examples 'something' { }
      to: RSpec.shared_examples 'something' { }

* 2 conversions
    from: describe 'something' { }
      to: RSpec.describe 'something' { }

* 20 conversions
    from: obj.should
      to: expect(obj).to

For more details: https://github.com/yujinakayama/transpec#supported-conversions
Modify cmd option in Guardfile

Not `bundle exec` cause following error

    Guard::RSpec failed to achieve its <run_all>, exception was:
    > [#CC0CB6320818] NoMethodError: undefined method `match' for nil:NilClass