Convert specs to RSpec 3.1.7 syntax with Transpec

This conversion is done by Transpec 2.3.8 with the following command:
    transpec

* 28 conversions
    from: == expected
      to: eq(expected)

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

* 7 conversions
    from: obj.stub(:message)
      to: allow(obj).to receive(:message)

* 6 conversions
    from: obj.should_receive(:message)
      to: expect(obj).to receive(:message)

* 4 conversions
    from: proc { }.should
      to: expect { }.to

* 2 conversions
    from: proc { }.should_not
      to: expect { }.not_to

* 1 conversion
    from: obj.should_not
      to: expect(obj).not_to

For more details: https://github.com/yujinakayama/transpec#supported-conversions
use rspec ~> 3.0
use ruby 2.0 and 2.1 instead of 2.0.0 on travis
remove space in empty blocks
use single quotes string literals
remove extra empty lines
remove space before block braces
use `unless` instead of `if !`
use format instead of %
use underscores to separate long numbers
cleanup progress output spec
fast finish travis
add rubocop to travis
development dependency on rubocop
use guard clauses
stick with is_a? everywhere
use do ... end for multiline blocks
remove unneeded adding lib to load path
safe assignments in conditions
rename set_terminal_title to terminal_title