Updated travis build scripts (from rspec-dev)
Merge pull request #135 from rspec/update-travis-build-scripts-2014-12-08-for-master

Updates from rspec-dev (2014-12-08)
Updated travis build scripts (from rspec-dev)
Merge pull request #138 from rspec/update-travis-build-scripts-2014-12-17-for-master

Updates from rspec-dev (2014-12-17)
Allow StdErrSplitter to conform to the full stderr iterface

This is required to support the `to_std(out|err)_from_any_process`
matchers, which reopen $stderr to a Tempfile.
Merge pull request #139 from alexgenco/stderr_splitter

Allow StdErrSplitter to conform to full $stderr interface
Optimize `RSpec::CallerFilter`.

- Use `caller_locations` rather than `caller`. It's apparently
  much faster. I suspect that it's due to the fact that `caller`
  has to due some extra calculation for each stack frame in order
  to combine them into a full line description string, where as
  `caller_locations` returns an object with the separate stack
  frame attributes and does the full line description calculation
  when you call `to_s`.
- Immediately return when we have the line, rather than updating `i`
  and `increment` for now reason.
Merge pull request #140 from rspec/optimize-caller-filter

Optimize `RSpec::CallerFilter`.
Test EncodedSring#to_s for undefined conversion / invalid byte sequence
Assert EncodedString fails splitting a string with invalid byte sequence
Simplify EncodedString conversions; fix ArgumentError raised from #split

Also, make Rubocop happy
Clarify encoding failures and provide better replacement strings for undefined conversions