DEV: always run migrations for plugins in dev

Otherwise devs forget to run plugin migrations and get confused when test
does not work. We ship critical migrations in the bundled polls plugin.

bin/rake

@@ -1,4 +1,12 @@
 #!/usr/bin/env ruby
+
+if ENV['RAILS_ENV'] == 'test' && ENV['LOAD_PLUGINS'].nil?
+  if ARGV.include?('db:migrate')
+    STDERR.puts "You are attempting to run migrations in your test environment and are not loading plugins, setting LOAD_PLUGINS to 1"
+    ENV['LOAD_PLUGINS'] = '1'
+  end
+end
+
 require_relative '../config/boot'
 require 'rake'
 Rake.application.run