Set upper limit of elasticsearch-transport faraday dependency to "< 1"

Faraday recently released 1.0, and elasticsearch-transport was on 0.xx.
Breaking changes in 1.0 plus the gemspec allowing the update to 1.x can
cause unclear problems.

Author: taylorthurlow

elasticsearch-transport/elasticsearch-transport.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |s|
   s.required_ruby_version = '>= 1.9'
 
   s.add_dependency "multi_json"
-  s.add_dependency "faraday"
+  s.add_dependency "faraday", '>= 0.14', "< 1"
 
   if defined?(RUBY_VERSION) && RUBY_VERSION < '1.9'
     s.add_dependency "system_timer"