Update ruby-rspec-core to 2.14.8.

### 2.14.8 / 2014-02-27
[Full Changelog](http://github.com/rspec/rspec-core/compare/v2.14.7...v2.14.8)

Bug fixes:

* Fix regression with the `TextMateFormatter` that prevented backtrace links
  from being clickable. (Stefan Daschek)

### 2.14.7 / 2013-10-29
[full changelog](http://github.com/rspec/rspec-core/compare/v2.14.6...v2.14.7)

Bug fixes:

* Fix regression in 2.14.6 that broke the Fivemat formatter.
  It depended upon either
  `example.execution_result[:exception].pending_fixed?` (which
  was removed in 2.14.6 to fix an issue with frozen error objects)
  or `RSpec::Core::PendingExampleFixedError` (which was renamed
  to `RSpec::Core::Pending::PendingExampleFixedError` in 2.8.
  This fix makes a constant alias for the old error name.
  (Myron Marston)

### 2.14.6 / 2013-10-15
[full changelog](http://github.com/rspec/rspec-core/compare/v2.14.5...v2.14.6)

Bug fixes:

* Format stringified numbers correctly when mathn library is loaded.
  (Jay Hayes)
* Fix an issue that prevented the use of frozen error objects. (Lars Gierth)

(taca)