Update rubocop requirement from ~> 0.87.0 to ~> 0.89.1

Updates the requirements on [rubocop](https://github.com/rubocop-hq/rubocop) to permit the latest version.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v0.87.0...v0.89.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

.rubocop.yml

@@ -17,7 +17,7 @@ Layout/LineLength:
   Enabled: false
 
 Metrics/AbcSize:
-  Max: 39.29
+  Max: 44.11
 
 Metrics/CyclomaticComplexity:
   Max: 19

Gemfile

@@ -12,7 +12,7 @@ end
 group :development do
   gem 'rake', '~> 13.0'
   gem 'rspec', '~> 3.9'
-  gem 'rubocop', '~> 0.87.0'
+  gem 'rubocop', '~> 0.89.1'
   gem 'rubocop-performance', '~> 1.7'
   gem 'rubocop-rspec', '~> 1.41'
   gem 'truthy', '~> 1.0'

bin/coveralls

@@ -1,7 +1,7 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
-lib = File.expand_path(File.dirname(__FILE__) + '/../lib')
+lib = File.expand_path('../lib', __dir__)
 $LOAD_PATH.unshift(lib) if File.directory?(lib) && !$LOAD_PATH.include?(lib)
 
 require 'coveralls'

lib/coveralls/api.rb

@@ -53,8 +53,8 @@ def disable_net_blockers!
         begin
           require 'webmock'
 
-          allow = WebMock::Config.instance.allow || []
-          WebMock::Config.instance.allow = [*allow].push API_HOST
+          allow = Array(WebMock::Config.instance.allow)
+          WebMock::Config.instance.allow = allow.push API_HOST
         rescue LoadError
         rescue StandardError => e
           # TODO: Add error action

lib/coveralls/rake/task.rb

@@ -7,7 +7,7 @@ module Coveralls
   class RakeTask < ::Rake::TaskLib
     include ::Rake::DSL if defined?(::Rake::DSL)
 
-    def initialize(*_args)
+    def initialize(*_args) # rubocop:disable Lint/MissingSuper
       namespace :coveralls do
         desc 'Push latest coverage results to Coveralls.io'
         task :push do

spec/spec_helper.rb

@@ -49,7 +49,7 @@ def setup_formatter
 
 def stub_api_post
   body = '{"message":"","url":""}'
-  stub_request(:post, Coveralls::API::API_BASE + '/jobs').with(
+  stub_request(:post, "#{Coveralls::API::API_BASE}/jobs").with(
     headers: {
       'Accept'          => '*/*; q=0.5, application/xml',
       'Accept-Encoding' => 'gzip, deflate',
@@ -60,12 +60,10 @@ def stub_api_post
   ).to_return(status: 200, body: body, headers: {})
 end
 
-def silence
+def silence(&block)
   return yield if ENV['silence'] == 'false'
 
-  silence_stream(STDOUT) do
-    yield
-  end
+  silence_stream($stdout, &block)
 end
 
 def silence_stream(stream)