Use default Rake tasks and scripts

.gitignore

@@ -1,6 +1,7 @@
-/vendor/gems
 .bundle
-bin
 /*.gem
-Gemfile.lock
 /tmp
+/vendor/gems
+bin
+Gemfile.lock
+pkg/*.gem

Rakefile

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+require "bundler/gem_tasks"
+require "rspec/core/rake_task"
+
+RSpec::Core::RakeTask.new(:spec)
+
+task :default => :spec

jekyll-mentions.gemspec

@@ -15,6 +15,7 @@ Gem::Specification.new do |s|
   s.add_dependency "html-pipeline", "~> 2.3"
   s.add_dependency "jekyll", "~> 3.0"
 
+  s.add_development_dependency "rake", "~> 12.0"
   s.add_development_dependency "rspec", "~> 3.0"
   s.add_development_dependency "rubocop", "0.51"
 end

script/cibuild

@@ -1,5 +1,7 @@
 #! /bin/sh
 
-bundle exec rspec
-bundle exec rubocop -S -D
-gem build jekyll-mentions.gemspec
+set -e
+
+script/test
+script/fmt
+bundle exec rake build

script/fmt

@@ -0,0 +1,10 @@
+#!/bin/bash
+set -e
+
+echo "Rubocop $(bundle exec rubocop --version)"
+bundle exec rubocop -D -E $@
+success=$?
+if ((success != 0)); then
+   echo -e "\nTry running \`script/fmt -a\` to automatically fix errors"
+fi
+exit $success

script/release

@@ -0,0 +1,7 @@
+#!/bin/sh
+# Tag and push a release.
+
+set -e
+
+script/cibuild
+bundle exec rake release

script/test

@@ -0,0 +1,4 @@
+#!/bin/bash
+set -ex
+
+bundle exec rspec "$@"