diff --git a/.rubocop.yml b/.rubocop.yml
index 6cca6d2..8b76fd4 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,12 +1,15 @@
 AllCops:
   Include:
-    - './Rakefile'
-    - 'instapaper.gemspec'
-    - 'lib/**/*.rb'
-    - 'spec/**/*.rb'
+    - "./Rakefile"
+    - "instapaper.gemspec"
+    - "lib/**/*.rb"
+    - "spec/**/*.rb"
   DisplayCopNames: true
   NewCops: enable
 
+Gemspec/RequireMFA:
+  Enabled: false
+
 Metrics/BlockLength:
   Max: 36
   Exclude:
@@ -15,7 +18,7 @@ Metrics/BlockLength:
 Metrics/BlockNesting:
   Max: 2
 
-Metrics/LineLength:
+Layout/LineLength:
   AllowURI: true
   Enabled: false
 
@@ -29,10 +32,10 @@ Metrics/ParameterLists:
 
 Style/CollectionMethods:
   PreferredMethods:
-    map:      'collect'
-    reduce:   'inject'
-    find:     'detect'
-    find_all: 'select'
+    map: "collect"
+    reduce: "inject"
+    find: "detect"
+    find_all: "select"
 
 Style/Documentation:
   Enabled: false
@@ -53,15 +56,15 @@ Layout/SpaceInsideHashLiteralBraces:
   EnforcedStyle: no_space
 
 Style/TrailingCommaInArguments:
-  EnforcedStyleForMultiline: 'comma'
+  EnforcedStyleForMultiline: "comma"
 
 Style/TrailingCommaInArrayLiteral:
-  EnforcedStyleForMultiline: 'comma'
+  EnforcedStyleForMultiline: "comma"
 
 Style/TrailingCommaInHashLiteral:
-  EnforcedStyleForMultiline: 'comma'
+  EnforcedStyleForMultiline: "comma"
 
-Style/FileName:
+Naming/FileName:
   Exclude:
     - Rakefile
     - Gemfile
diff --git a/Gemfile b/Gemfile
index 621ba6f..f69d498 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,6 +7,7 @@ gem 'jruby-openssl', platforms: :jruby
 gem 'json', platforms: :mri_19
 
 group :development do
+  gem 'bundler'
   gem 'kramdown'
 end
 
diff --git a/instapaper.gemspec b/instapaper.gemspec
index 6c6f97b..671489a 100644
--- a/instapaper.gemspec
+++ b/instapaper.gemspec
@@ -8,7 +8,6 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'multi_json', '~> 1'
   spec.add_dependency 'simple_oauth', '~> 0.3'
   spec.add_dependency 'virtus', '~> 1'
-  spec.add_development_dependency 'bundler'
   spec.author        = 'Steve Agalloco'
   spec.description   = "Ruby Client for Instapaper's Full API"
   spec.email         = 'steve.agalloco@gmail.com'
@@ -20,4 +19,5 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = '>= 2.0.0'
   spec.summary       = 'Ruby Instapaper Client'
   spec.version       = Instapaper::VERSION
+  spec.metadata['rubygems_mfa_required'] = 'true'
 end
diff --git a/lib/instapaper/api/folders.rb b/lib/instapaper/api/folders.rb
index ad4c435..a2dc63a 100644
--- a/lib/instapaper/api/folders.rb
+++ b/lib/instapaper/api/folders.rb
@@ -18,7 +18,7 @@ def add_folder(title)
 
       # Deletes the folder and moves any articles in it to the Archive.
       # @param folder_id [String] The id of the folder.
-      def delete_folder(folder_id)
+      def delete_folder(folder_id) # rubocop:disable Naming/PredicateMethod
         perform_post_with_unparsed_response('/api/1.1/folders/delete', folder_id: folder_id)
         true
       end
@@ -27,7 +27,7 @@ def delete_folder(folder_id)
       # @param order [Array] An array of folder_id:position pairs joined by commas.
       # @example Ordering folder_ids 100, 200, and 300
       #   Instapaper.set_order(['100:1','200:2','300:3'])
-      def set_order(order = []) # rubocop:disable Naming/AccessorMethodName
+      def set_order(order = [])
         perform_post_with_objects('/api/1.1/folders/set_order', {order: order.join(',')}, Instapaper::Folder)
       end
     end
diff --git a/lib/instapaper/api/highlights.rb b/lib/instapaper/api/highlights.rb
index b39e94c..d6e1b5a 100644
--- a/lib/instapaper/api/highlights.rb
+++ b/lib/instapaper/api/highlights.rb
@@ -24,7 +24,7 @@ def add_highlight(bookmark_id, options = {})
       # Delete a highlight
       # @param highlight_id [String, Integer]
       # @return [Boolean]
-      def delete_highlight(highlight_id, options = {})
+      def delete_highlight(highlight_id, options = {}) # rubocop:disable Naming/PredicateMethod
         perform_post_with_unparsed_response("/api/1.1/highlights/#{highlight_id}/delete", options)
         true
       end
diff --git a/lib/instapaper/bookmark_list.rb b/lib/instapaper/bookmark_list.rb
index 777d490..5307a56 100644
--- a/lib/instapaper/bookmark_list.rb
+++ b/lib/instapaper/bookmark_list.rb
@@ -8,9 +8,9 @@ class BookmarkList
 
     values do
       attribute :user, Instapaper::User
-      attribute :bookmarks, Array[Instapaper::Bookmark]
-      attribute :highlights, Array[Instapaper::Highlight]
-      attribute :delete_ids, Array[Integer]
+      attribute :bookmarks, [Instapaper::Bookmark]
+      attribute :highlights, [Instapaper::Highlight]
+      attribute :delete_ids, [Integer]
     end
 
     def each(&block)
diff --git a/lib/instapaper/http/utils.rb b/lib/instapaper/http/utils.rb
index 972fa6e..8a19522 100644
--- a/lib/instapaper/http/utils.rb
+++ b/lib/instapaper/http/utils.rb
@@ -42,7 +42,7 @@ def perform_post_with_object(path, options, klass)
       # @param klass [Class]
       def perform_request_with_object(request_method, path, options, klass)
         response = perform_request(request_method, path, options)
-        response = response.is_a?(Array) ? response.first : response
+        response = response.first if response.is_a?(Array)
         klass.new(coerce_hash(response))
       end
 
diff --git a/spec/instapaper/http/response_spec.rb b/spec/instapaper/http/response_spec.rb
index 28f5967..d206ae9 100644
--- a/spec/instapaper/http/response_spec.rb
+++ b/spec/instapaper/http/response_spec.rb
@@ -30,12 +30,15 @@ def parse(_)
 
   describe '#valid?' do
     context 'when http error' do
+      it 'should be invalid'
     end
 
     context 'when body unparseable' do
+      it 'should be invalid'
     end
 
     context 'when error in body' do
+      it 'should be invalid'
     end
   end
 end