Fixes checking for github bots in contributors

CONTRIBUTORS.md

@@ -93,5 +93,4 @@ submit the change with your pull request.
 
 ### Security and Dependency Updates
 - DeppBot / [deppbot](https://github.com/deppbot)
-- dependabot[bot] / [dependabot-bot] / [dependabot] (https://github.com/dependabot-bot)
-- dependabot / [dependabot](https://github.com/dependabot)
+- dependabot[bot]  (https://github.com/dependabot-bot)

script/check_contributors_md.rb

@@ -1,6 +1,7 @@
 #!/usr/bin/env ruby
 
 puts "Checking to see if you're in CONTRIBUTORS.md..."
+
 if ENV['TRAVIS']
   if ENV['TRAVIS_PULL_REQUEST']
     require 'httparty'
@@ -18,7 +19,7 @@ if ENV['TRAVIS']
   end
 else
   author = `git config github.user`.chomp
-  if $CHILD_STATUS.exitstatus.positive?
+  if $?.exitstatus.positive?
     abort %(
 Couldn't determine your GitHub username, and not in a Travis PR build
 Please set it using
@@ -27,6 +28,9 @@ Please set it using
   end
 end
 
+author.sub! '[', '\\['
+author.sub! ']', '\\]'
+
 unless system('grep', '-i', author, 'CONTRIBUTORS.md')
   abort %(
 Thanks for your contribution, #{author}!