Fix Layout/SpaceAroundOperators: Operator = should be surrounded by a single space.

Author: bronzdoc

test/rubygems/test_gem_commands_build_command.rb

@@ -244,7 +244,7 @@ def test_can_find_gemspecs_without_dot_gemspec
 
  def test_execute_without_gem_name
  some_gem = util_spec "some_gem"
- gemspec_dir  = File.join(@tempdir, "build_command_gem")
+ gemspec_dir = File.join(@tempdir, "build_command_gem")
  gemspec_file = File.join(gemspec_dir, some_gem.spec_name)
 
  FileUtils.mkdir_p(gemspec_dir)