Require rubocop v0.81+ / Update rubocop configuration (#112)

* require rubocop v0.81~

* Add new cops

Author: toshimaru

.rubocop.yml

@@ -8,27 +8,31 @@ AllCops:
 
 Metrics/MethodLength:
   Enabled: false
-
 Metrics/AbcSize:
   Enabled: false
-
 Metrics/ClassLength:
   Enabled: false
 
-Style/WordArray:
-  Enabled: false
-
 Naming/FileName:
   Enabled: false
 
 Layout/LineLength:
   Enabled: false
+Layout/SpaceAroundMethodCallOperator:
+  Enabled: true
 
-Style/HashEachMethods:
+Lint/RaiseException:
+  Enabled: true
+Lint/StructNewOverride:
   Enabled: true
 
+Style/WordArray:
+  Enabled: false
+Style/HashEachMethods:
+  Enabled: true
 Style/HashTransformKeys:
   Enabled: true
-
 Style/HashTransformValues:
   Enabled: true
+Style/ExponentialNotation:
+  Enabled: true

Gemfile

@@ -7,5 +7,5 @@ gem 'minitest-reporters'
 gem 'minitest'
 gem 'pry'
 gem 'rake'
-gem 'rubocop'
+gem 'rubocop', '~> 0.81'
 gem 'simplecov', '~> 0.17.1'