gpg_requirement: rename to gpg2_requirement

Library/Homebrew/compat/requirements.rb

@@ -3,7 +3,8 @@ require "requirements"
 XcodeDependency            = XcodeRequirement
 MysqlDependency            = MysqlRequirement
 PostgresqlDependency       = PostgresqlRequirement
-GPGDependency              = GPGRequirement
+GPGDependency              = GPG2Requirement
+GPGRequirement             = GPG2Requirement
 TeXDependency              = TeXRequirement
 MercurialDependency        = MercurialRequirement
 GitDependency              = GitRequirement

Library/Homebrew/dependency_collector.rb

@@ -99,7 +99,7 @@ class DependencyCollector
     when :macos      then MinimumMacOSRequirement.new(tags)
     when :mysql      then MysqlRequirement.new(tags)
     when :postgresql then PostgresqlRequirement.new(tags)
-    when :gpg        then GPGRequirement.new(tags)
+    when :gpg        then GPG2Requirement.new(tags)
     when :fortran    then FortranRequirement.new(tags)
     when :mpi        then MPIRequirement.new(*tags)
     when :tex        then TeXRequirement.new(tags)

Library/Homebrew/requirements.rb

 require "requirement"
 require "requirements/apr_requirement"
 require "requirements/fortran_requirement"
-require "requirements/gpg_requirement"
+require "requirements/gpg2_requirement"
 require "requirements/language_module_requirement"
 require "requirements/minimum_macos_requirement"
 require "requirements/maximum_macos_requirement"

Library/Homebrew/requirements/gpg_requirement.rb → Library/Homebrew/requirements/gpg2_requirement.rb

 require "requirement"
 require "gpg"
 
-class GPGRequirement < Requirement
+class GPG2Requirement < Requirement
   fatal true
   default_formula "gnupg2"