Add :spec rake task

- use this in github action

Author: aramprice

.github/workflows/ruby.yml

@@ -11,4 +11,4 @@ jobs:
       - uses: ruby/setup-ruby@v1
         with:
           bundler-cache: true # runs 'bundle install' and caches installed gems automatically
-      - run: bundle exec rspec
+      - run: bundle exec rake spec

Gemfile

@@ -8,6 +8,6 @@ gem 'rubyzip'
 gem 'activesupport'
 gem 'activemodel'
 gem 'rspec'
+gem 'simplecov', require: false
 gem 'timecop'
 gem 'webmock'
-gem 'simplecov', require: false, group: :test

Rakefile

@@ -1,4 +1,3 @@
-require 'rspec/core/rake_task'
 require_relative 'lib/stemcell/builder'
 
 import 'lib/tasks/build/aws.rake'
@@ -13,3 +12,6 @@ import 'lib/tasks/package/vsphere_ova.rake'
 
 import 'lib/tasks/publish/azure.rake'
 import 'lib/tasks/publish/gcp.rake'
+
+require 'rspec/core/rake_task'
+RSpec::Core::RakeTask.new(:spec)