Updated travis build scripts (from rspec-dev)
Merge pull request #1801 from rspec/update-travis-build-scripts-2014-12-08-for-master

Updates from rspec-dev (2014-12-08)
Revert "Updated travis build scripts (from rspec-dev)"

This reverts commit f1b937bf7a6b8f09a26de7aeb230092ccbd2c3cd.

[ci skip]
Updated travis build scripts (from rspec-dev)
Merge pull request #1802 from rspec/update-travis-build-scripts-2014-12-08-for-master

Updates from rspec-dev (2014-12-08)
Refactor how context hooks get run.

- Move `descendant_filtered_examples.empty?` check
  out into the `run` method.
- This allows us to only create the instances for
  the context hooks if we need to actually run the
  hooks.
- Move `before_context_ivars.clear` into
  `run_after_context_hooks`. This gives it
  parity with `run_before_context_hooks`.
Remove unneeded layer of indirection.
Fix doc string.
Apply module inclusion to individual examples when filtered.

Previously it only applied to filtered groups. Luckily,
ruby’s object model supports this very easily through
the use of singleton classes.
Refactor configuration module implementation.

When configuring an example, we only want to include
modules (extending one would not make sense), so this
refactoring allows us to skip that part.
Ensure shared contexts applied to one example have their hooks run.
Got things to work on 1.8.7.
Run `:context` hooks from shared contexts that apply to one example.
Make :context hooks in config apply to individual matching examples.
Skip specs failing due to a JRuby 1.7 bug when run in ruby 2.0 mode.