Resolve mocha deprecation warning

Mocha deprecation warning at test_helper.rb:7 `require':
Require 'mocha/test_unit', 'mocha/minitest' or 'mocha/api' instead of
'mocha/setup'.

test/test_helper.rb

@@ -4,7 +4,7 @@
 require 'minitest/autorun'
 require 'minitest/rg'
 require 'minitest/line/describe_track'
-require 'mocha/setup'
+require 'mocha/minitest'
 require 'global_uid'
 require 'phenix'
 require 'pry'