Declare a dependency on logstash-core snapshot instead of the release version

Author: ph

logstash-codec-rubydebug.gemspec

@@ -20,7 +20,7 @@ Gem::Specification.new do |s|
  s.metadata = { "logstash_plugin" => "true", "logstash_group" => "codec" }
 
  # Gem dependencies
- s.add_runtime_dependency "logstash-core", ">= 2.0.0", "< 3.0.0"
+ s.add_runtime_dependency "logstash-core", "~> 2.0.0.snapshot"
 
  s.add_runtime_dependency 'awesome_print'