Apply automatic rubocop fixes

db/seeds/fibonacci/exercise.rb

@@ -1,2 +1,3 @@
-def fibonacci(n)
-end
+# frozen_string_literal: true
+
+def fibonacci(n); end

db/seeds/fibonacci/exercise_spec_1.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require './exercise'
 
 describe '#fibonacci' do

db/seeds/fibonacci/exercise_spec_2.rb

@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 require './exercise'
 
 describe '#fibonacci' do
   it 'works recursively' do
     @n = 16
-    expect(self).to receive(:fibonacci).and_call_original.at_least(@n ** 2).times
+    expect(self).to receive(:fibonacci).and_call_original.at_least(@n**2).times
     fibonacci(@n)
   end
 end

db/seeds/fibonacci/exercise_spec_3.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require './exercise'
 require './reference'
 

db/seeds/fibonacci/reference.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Reference
   def fibonacci(n)
     n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2)