set default_codec doc attribute 

Bump version and update change Fixes #14

Minor: reformat meetup.rb Fixes #12

[skip ci] update gemspec summary 

Version bump For elastic/logstash#7993 [ci skip]

bump patch level for doc generation 

Update logstash-input-meetup.gemspec 

dependency logstash-core-plugin-api ~> 1.0 

dependency logstash-core >= 2.0.0.beta2 < 3.0.0 

dependency logstash-core >= 2.0.0.snapshot < 3.0.0