Fix CI failures due to net-telnet 0.2.0 not supporting ruby < 2.3 anymore

Fixed up minor PR issues.

Signed-off-by: Ben Abrams <[email protected]>

Author: majormoses

CHANGELOG.md

@@ -6,9 +6,8 @@ Which is based on [Keep A Changelog](http://keepachangelog.com/)
 
 ## [Unreleased]
 
-## [3.1.2] - 2018
 ### Added 
- - metrics-docker-stats.rb: New Regex flag to filter container using Regex String.
+ - metrics-docker-stats.rb: New option `--container-list-regex` to filter containers using Regex String (@parin921996).
 
 ## [3.1.1] - 2018
 ### Fixed

lib/sensu-plugins-docker/version.rb

@@ -2,7 +2,7 @@ module SensuPluginsDocker
   module Version
     MAJOR = 3
     MINOR = 1
-    PATCH = 2
+    PATCH = 1
 
     VER_STRING = [MAJOR, MINOR, PATCH].compact.join('.')
   end

sensu-plugins-docker.gemspec

@@ -38,6 +38,8 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'codeclimate-test-reporter', '~> 0.4'
   s.add_development_dependency 'github-markup',             '~> 1.3'
   s.add_development_dependency 'kitchen-docker',            '~> 2.6'
+  # TODO: remove this pin when we remove ruby 2.3 support, see: https://github.com/ruby/net-telnet/issues/14 for more information
+  s.add_development_dependency 'net-telnet',                '0.1.1'
   s.add_development_dependency 'pry',                       '~> 0.10'
   s.add_development_dependency 'rake',                      '~> 10.0'
   s.add_development_dependency 'redcarpet',                 '~> 3.2'