Log Message:
Update ruby-rspec-core to 3.3.0.

### 3.3.0 / 2015-06-12
[Full Changelog](http://github.com/rspec/rspec-core/compare/v3.2.3...v3.3.0)

Enhancements:

* Expose the reporter used to run examples via `RSpec::Core::Example#reporter`.
  (Jon Rowe, #1866)
* Make `RSpec::Core::Reporter#message` a public supported API. (Jon Rowe, #1866)
* Allow custom formatter events to be published via
  `RSpec::Core::Reporter#publish(event_name, hash_of_attributes)`. (Jon Rowe, #1869)
* Remove dependency on the standard library `Set` and replace with \ 
`RSpec::Core::Set`.
  (Jon Rowe, #1870)
* Assign a unique id to each example and group so that they can be
  uniquely identified, even for shared examples (and similar situations)
  where the location isn't unique. (Myron Marston, #1884)
* Use the example id in the rerun command printed for failed examples
  when the location is not unique. (Myron Marston, #1884)
* Add `config.example_status_persistence_file_path` option, which is
  used to persist the last run status of each example. (Myron Marston, #1888)
* Add `:last_run_status` metadata to each example, which indicates what
  happened the last time an example ran. (Myron Marston, #1888)
* Add `--only-failures` CLI option which filters to only the examples
  that failed the last time they ran. (Myron Marston, #1888)
* Add `--next-failure` CLI option which allows you to repeatedly focus
  on just one of the currently failing examples, then move on to the
  next failure, etc. (Myron Marston, #1888)
* Make `--order random` ordering stable, so that when you rerun a
  subset with a given seed, the examples will be order consistently
  relative to each other. (Myron Marston, #1908)
* Set example group constant earlier so errors when evaluating the context
  include the example group name (Myron Marson, #1911)
* Make `let` and `subject` threadsafe. (Josh Cheek, #1858)
* Add version information into the JSON formatter. (Mark Swinson, #1883)
* Add `--bisect` CLI option, which will repeatedly run your suite in
  order to isolate the failures to the smallest reproducible case.
  (Myron Marston, #1917)
* For `config.include`, `config.extend` and `config.prepend`, apply the
  module to previously defined matching example groups. (Eugene Kenny, #1935)
* When invalid options are parsed, notify users where they came from
  (e.g. `.rspec` or `~/.rspec` or `ENV['SPEC_OPTS']`) so they can
  easily find the source of the problem. (Myron Marston, #1940)
* Add pending message contents to the json formatter output. (Jon Rowe, #1949)
* Add shared group backtrace to the output displayed by the built-in
  formatters for pending examples that have been fixed. (Myron Marston, #1946)
* Add support for `:aggregate_failures` metadata. Tag an example or
  group with this metadata and it'll use rspec-expectations'
  `aggregate_failures` feature to allow multiple failures in an example
  and list them all, rather than aborting on the first failure. (Myron
  Marston, #1946)
* When no formatter implements #message add a fallback to prevent those
  messages being lost. (Jon Rowe, #1980)
* Profiling examples now takes into account time spent in `before(:context)`
  hooks. (Denis Laliberté, Jon Rowe, #1971)
* Improve failure output when an example has multiple exceptions, such
  as one from an `it` block and one from an `after` block. (Myron Marston, #1985)

Bug Fixes:

* Handle invalid UTF-8 strings within exception methods. (Benjamin Fleischer, #1760)
* Fix Rake Task quoting of file names with quotes to work properly on
  Windows. (Myron Marston, #1887)
* Fix `RSpec::Core::RakeTask#failure_message` so that it gets printed
  when the task failed. (Myron Marston, #1905)
* Make `let` work properly when defined in a shared context that is applied
  to an individual example via metadata. (Myron Marston, #1912)
* Ensure `rspec/autorun` respects configuration defaults. (Jon Rowe, #1933)
* Prevent modules overriding example group defined methods when included,
  prepended or extended by config defined after an example group. (Eugene Kenny, \ 
#1935)
* Fix regression which caused shared examples to be mistakenly run when specs
  where filtered to a particular location.  (Ben Axnick, #1963)
* Fix time formatting logic so that it displays 70 seconds as "1 minute,
  10 seconds" rather than "1 minute, 1 second". (Paul Brennan, #1984)
* Fix regression where the formatter loader would allow duplicate formatters.
  (Jon Rowe, #1990)