validate config file encoding when containing non-ascii characters

Fixes #1468
Cleaning gems dependencies from the logstash.gemspec

Fixes #2274
Generating a new lock files with Bundler 1.7.9

Fixes #2274
typo

Fixes #2274
update pipeline to call teardown of output workers when :workers > 1

Fixes #2180
add a generic spec helper where all logstash specs referre to and where they can get for example helper classes that makes running test easier
upgrade rspec to 2.99, prior to be upgraded to final 3.0 branch
change the current example reference to the customary rspec 3 way
Upgraded it to rspec 3.1.x, start the first style refactoring within the
conditionals_spec to make them more clear and disabled the json_spec (to
be enabled later) as it was interfering with others.

Added also a generic spec_helper where the helper classes should be
living.
add more operators specs
make the config spec more rspec alike
Made the event_spec more RSpec 3 friendly, using the time to also get
rid of insist, reject, and companions.
ammend previous commit
Add an option throw LOGSTASH_TEST=true to use the documentation
formatter as an rspec formatter as it helps while debugging.
ammend rspec import
divert the configuration using the documentation format within the test case, so all deps are installed
put the rspec into the spec helper
use one test per time format so it gets clear
update the ci_reporter
ammend previous commit