Use RuboCop 0.84.0

- this enables each of the new Cops and marks each with the version
they appeared in

.rubocop.yml

@@ -21,12 +21,27 @@ Gemspec:
 Layout:
   Enabled: true
 
+Layout/EmptyLinesAroundAttributeAccessor: # (0.83)
+  Enabled: true
+
+Layout/SpaceAroundMethodCallOperator: # (0.82)
+  Enabled: true
+
 Layout/LineLength:
   Max: 120
 
 Lint:
   Enabled: true
 
+Lint/DeprecatedOpenSSLConstant: # (0.84)
+  Enabled: true
+
+Lint/RaiseException: # (0.81)
+  Enabled: true
+
+Lint/StructNewOverride: # (0.81)
+  Enabled: true
+
 Naming:
   Enabled: true
   Exclude:
@@ -42,9 +57,6 @@ Style/BlockDelimiters:
   Enabled: true
   IgnoredMethods: [] # Workaround rubocop bug: https://github.com/rubocop-hq/rubocop/issues/6179
 
-Style/BracesAroundHashParameters:
-  Enabled: true
-
 Style/ClassAndModuleChildren:
   Enabled: true
   Exclude:

lib/rack/attack/cache.rb

@@ -12,6 +12,7 @@ module Rack
       end
 
       attr_reader :store
+
       def store=(store)
         @store =
           if (proxy = BaseProxy.lookup(store))

lib/rack/attack/check.rb

@@ -4,6 +4,7 @@ module Rack
   class Attack
     class Check
       attr_reader :name, :block, :type
+
       def initialize(name, options = {}, &block)
         @name = name
         @block = block

lib/rack/attack/throttle.rb

@@ -6,6 +6,7 @@ module Rack
       MANDATORY_OPTIONS = [:limit, :period].freeze
 
       attr_reader :name, :limit, :period, :block, :type
+
       def initialize(name, options, &block)
         @name = name
         @block = block

rack-attack.gemspec

@@ -37,7 +37,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency "minitest-stub-const", "~> 0.6"
   s.add_development_dependency 'rack-test', "~> 1.0"
   s.add_development_dependency 'rake', "~> 13.0"
-  s.add_development_dependency "rubocop", "0.78.0"
+  s.add_development_dependency "rubocop", "0.84.0"
   s.add_development_dependency "rubocop-performance", "~> 1.5.0"
   s.add_development_dependency "timecop", "~> 0.9.1"