Suppress RuboCop offenses

Follow up rubocop/rubocop#6954.

This PR applied `rubocop --auto-gen-config`.

.rubocop_todo.yml

@@ -1,11 +1,20 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2019-03-13 01:21:08 +0900 using RuboCop version 0.65.0.
+# on 2019-05-01 18:41:27 -0500 using RuboCop version 0.68.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
+# Offense count: 12
+InternalAffairs/NodeDestructuring:
+  Exclude:
+    - 'lib/rubocop/cop/performance/casecmp.rb'
+    - 'lib/rubocop/cop/performance/detect.rb'
+    - 'lib/rubocop/cop/performance/redundant_block_call.rb'
+    - 'lib/rubocop/cop/performance/regexp_match.rb'
+    - 'lib/rubocop/cop/performance/string_replacement.rb'
+
 # Offense count: 7
 Metrics/AbcSize:
   Max: 17
@@ -15,16 +24,25 @@ Metrics/AbcSize:
 Metrics/ClassLength:
   Max: 147
 
-# Offense count: 16
+# Offense count: 14
 # Configuration parameters: CountComments, ExcludedMethods.
 Metrics/MethodLength:
   Max: 14
 
-# Offense count: 41
+# Offense count: 40
 # Configuration parameters: Prefixes.
 # Prefixes: when, with, without
 RSpec/ContextWording:
-  Enabled: false
+  Exclude:
+    - 'spec/project_spec.rb'
+    - 'spec/rubocop/cop/performance/case_when_splat_spec.rb'
+    - 'spec/rubocop/cop/performance/count_spec.rb'
+    - 'spec/rubocop/cop/performance/detect_spec.rb'
+    - 'spec/rubocop/cop/performance/double_start_end_with_spec.rb'
+    - 'spec/rubocop/cop/performance/fixed_size_spec.rb'
+    - 'spec/rubocop/cop/performance/reverse_each_spec.rb'
+    - 'spec/rubocop/cop/performance/string_replacement_spec.rb'
+    - 'spec/rubocop/cop/performance/times_map_spec.rb'
 
 # Offense count: 88
 # Configuration parameters: Max.