Restore changes needed to run the schema plugin in the dummy app

- Remove the Ruby 2.7.4 restriction
- Load the manageiq-schema Gemfile instead of the dummy app Gemfile
- Delete the generated database.yml in favor of database.tmpl.yml
- Ignore the db/schema.rb that is generated
- Restore the v2_key

spec/dummy/.gitignore

@@ -27,3 +27,7 @@
 
 # Ignore master key for decrypting credentials and more.
 /config/master.key
+
+# Ignores for working with manageiq-schema plugin
+/config/database.yml
+/db/schema.rb

spec/dummy/certs/v2_key

@@ -0,0 +1,5 @@
+---
+:EZCRYPTO KEY FILE: KEEP THIS SECURE !
+:created: 2014-02-28 09:59:47 -0500
+:algorithm: aes-256-cbc
+:key: uXfIgSAUq5Oz8goc/zI8HOOo0SI++Sd9mfpgBanYIM4=

spec/dummy/config/boot.rb

@@ -1,3 +1,3 @@
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
+ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../../Gemfile', __dir__)
 
 require 'bundler/setup' # Set up gems listed in the Gemfile.

spec/dummy/config/database.tmpl.yml

@@ -0,0 +1,23 @@
+---
+base: &base
+  adapter: postgresql
+  encoding: utf8
+  username: root
+  password: smartvm
+  pool: 5
+  wait_timeout: 5
+  min_messages: warning
+
+development:
+  <<: *base
+  database: dummy_development
+  min_messages: notice
+
+production:
+  <<: *base
+  database: dummy_production
+
+test: &test
+  <<: *base
+  pool: 3
+  database: dummy_test