v0.5.5 compatible with logstash 6.0

Merge pull request #30 from mschneider82/patch-1

logstash6: upgrading http_client version

Release 0.5.4

Merge pull request #28 from gandalfb/version/logstash-5.5

version/logstash 5.5

Major release v0.5.0

Now compatible with logstash 5

Major release v0.2.0

Changes:

• response_keyrenamed to target which is used by other logstash plugins as well
• error handling via event tags, not fields
  • json or rest errors can be set to custom tags (array)
• fallback functionality to add a default hash, in case of http error (http code not 200 to 299) or json error
• request represents the HTTPClient config
• it is focussed on json
  • if it is post, the paramsare saved as bodyand dumped as json
  • for json the Logstash::JSON is used instead of "require json"
  • string only functionality is not well evolved
• extended test cases with travis-ci usage
• paramsmay also be used for a get
• url, body, params are sprintf'ed
• remove git client dependency within .gemspec; this lead to errors once installing the plugin on a remote server without git

v0.1.6

Now compatible with Logstash > 2.0.0.

v0.1.5

Fixed the sprintf bug. http://stackoverflow.com/questions/33250615/logstash-filter-rest-sent-field-references-incorrectly-it-always-reference-first