remove integration test that has been move into its own gem

Fixes #2270
Removing the gembag and the download of the vendored files since the logic was moved into their specific gems.

Fixes #2272
Update for windows to execute rake bootstrap and bin\logstash.bat

Fixes #2085
allow implicit agent using directly a flag in cli

Fixes #1296
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