Added the start of a new migration to use the Rate plugin

* Migration 9 will abort with a message if the Rate plugin isn't installed

  #1924

db/migrate/009_convert_member_rate_to_full_rates.rb

@@ -0,0 +1,21 @@
+RateMigrationErrorMessage = "ERROR: The Rate plugin is not installed.  Please install the Rate plugin or downgrade to version 0.1.0 of the Budget plugin."
+
+begin
+  require_dependency 'rate'
+rescue LoadError
+  raise Exception.new(RateMigrationErrorMessage)
+end
+
+class ConvertMemberRateToFullRates < ActiveRecord::Migration
+  def self.up
+    self.check_that_rate_plugin_is_installed
+  end
+  
+  def self.down
+    self.check_that_rate_plugin_is_installed
+  end
+  
+  def self.check_that_rate_plugin_is_installed
+    raise Exception.new(RateMigrationErrorMessage) unless Object.const_defined?("Rate")
+  end
+end