Bundle update rubocop and auto correct style issues

spec/integration/balancing_spec.rb

@@ -180,6 +180,6 @@ feature 'settling an order', js: true do
     end
     expect(page).to_not have_selector('form#new_order_article')
     expect(page).to have_content(new_article.name)
-    expect(order.order_articles.where(article_id: new_article.id)).to_not be nil
+    expect(order.order_articles.where(article_id: new_article.id)).to_not be_nil
   end
 end

spec/lib/bank_account_information_importer_spec.rb

@@ -8,7 +8,7 @@ describe BankTransaction do
     JSON
 
     importer = BankAccountInformationImporter.new(bank_account)
-    expect(importer.import!(content)).to be(nil)
+    expect(importer.import!(content)).to be_nil
   end
 
   it 'invalid JSON' do
@@ -241,7 +241,7 @@ describe BankTransaction do
     expect(bt.amount).to eq(-238.68)
     expect(bt.date).to eq('2019-02-13'.to_date)
     expect(bt.text).to eq('Hammersmith Inc.')
-    expect(bt.iban).to be(nil)
+    expect(bt.iban).to be_nil
     expect(bt.reference).to eq("Corvette Ersatzteile\nMartin Schöneicher, Inv# 123453423, Thx")
     expect(bt.receipt).to eq('Auslands-Überweisung')
   end
@@ -277,7 +277,7 @@ describe BankTransaction do
     expect(bt.amount).to eq(-12.3)
     expect(bt.date).to eq('2019-02-14'.to_date)
     expect(bt.text).to eq('superbank AG')
-    expect(bt.iban).to be(nil)
+    expect(bt.iban).to be_nil
     expect(bt.reference).to eq("Überweisung US, Wechselspesen u Provision")
     expect(bt.receipt).to eq('Spesen/Gebühren')
   end
@@ -399,14 +399,14 @@ describe BankTransaction do
     expect(bt2.text).to eq('CN2')
     expect(bt2.iban).to eq('CH9300762011623852957')
     expect(bt2.reference).to eq('RI2')
-    expect(bt2.receipt).to be(nil)
+    expect(bt2.receipt).to be_nil
 
     bt3 = bank_account.bank_transactions.find_by_external_id("T3")
     expect(bt3.amount).to eq(33)
     expect(bt3.date).to eq('2000-03-01'.to_date)
     expect(bt3.text).to eq('DN3')
-    expect(bt3.iban).to be(nil)
+    expect(bt3.iban).to be_nil
     expect(bt3.reference).to eq('')
-    expect(bt3.receipt).to be(nil)
+    expect(bt3.receipt).to be_nil
   end
 end

spec/lib/bank_transaction_reference_spec.rb

@@ -2,35 +2,35 @@ require_relative '../spec_helper'
 
 describe BankTransactionReference do
   it 'returns nil for empty input' do
-    expect(BankTransactionReference.parse('')).to be nil
+    expect(BankTransactionReference.parse('')).to be_nil
   end
 
   it 'returns nil for invalid string' do
-    expect(BankTransactionReference.parse('invalid')).to be nil
+    expect(BankTransactionReference.parse('invalid')).to be_nil
   end
 
   it 'returns nil for FS1A' do
-    expect(BankTransactionReference.parse('FS1A')).to be nil
+    expect(BankTransactionReference.parse('FS1A')).to be_nil
   end
 
   it 'returns nil for FS1.1A' do
-    expect(BankTransactionReference.parse('FS1.1A')).to be nil
+    expect(BankTransactionReference.parse('FS1.1A')).to be_nil
   end
 
   it 'returns nil for xFS1A1' do
-    expect(BankTransactionReference.parse('xFS1A1')).to be nil
+    expect(BankTransactionReference.parse('xFS1A1')).to be_nil
   end
 
   it 'returns nil for .FS1A1' do
-    expect(BankTransactionReference.parse('.FS1A1')).to be nil
+    expect(BankTransactionReference.parse('.FS1A1')).to be_nil
   end
 
   it 'returns nil for FS1A1x' do
-    expect(BankTransactionReference.parse('FS1A1x')).to be nil
+    expect(BankTransactionReference.parse('FS1A1x')).to be_nil
   end
 
   it 'returns nil for FS1A1.' do
-    expect(BankTransactionReference.parse('FS1A1.')).to be nil
+    expect(BankTransactionReference.parse('FS1A1.')).to be_nil
   end
 
   it 'returns correct value for FS1A1' do

spec/lib/foodsoft_config_spec.rb

@@ -9,7 +9,7 @@ describe FoodsoftConfig do
   end
 
   it 'returns an empty default value' do
-    expect(FoodsoftConfig[:protected][:LIUhniuyGNKUQTWfbiOQIWYexngo78hqexul]).to be nil
+    expect(FoodsoftConfig[:protected][:LIUhniuyGNKUQTWfbiOQIWYexngo78hqexul]).to be_nil
   end
 
   it 'returns a configuration value' do

spec/models/bank_transaction_spec.rb

@@ -59,7 +59,7 @@ describe BankTransaction do
     let!(:bank_transaction8) { create :bank_transaction, bank_account: bank_account, reference: "FS#{ordergroup.id}X10", amount: 10 }
 
     it 'ignores transaction with invalid reference' do
-      expect(bank_transaction1.assign_to_ordergroup).to be nil
+      expect(bank_transaction1.assign_to_ordergroup).to be_nil
     end
 
     it 'ignores transaction with invalid ordergroup' do