Adds silence option to argument array, and better matching to answer

This commit adds a silence option for users that have automated this
task and want to skip the destructive prompt. It also changes the
matching of a user's answer to explicitally check for 'y'.

sunspot_rails/lib/sunspot/rails/tasks.rb

@@ -14,13 +14,17 @@
   # $ rake sunspot:reindex[1000,Post]     # reindex only the Post model in
   #                                       # batchs of 1000
   # $ rake sunspot:reindex[,Post+Author]  # reindex Post and Author model
-  task :reindex, [:batch_size, :models] => [:environment] do |t, args|
-    puts "*Note: the reindex task will remove your current indexes and start from scratch."
-    puts "If you have a large dataset, reindexing can take a very long time, possibly weeks."
-    puts "This is not encouraged if you have anywhere near or over 1 million rows."
-    puts "Are you sure you want to drop your indexes and completely reindex? (y/n)"
-    answer = STDIN.gets.chomp
-    return false if answer == "n"
+  # $ rake sunspot:reindex[,,true]        # reindex silencing/skipping the boolean prompt
+  task :reindex, [:batch_size, :models, :silence] => [:environment] do |t, args|
+    args.with_defaults(:silence => false)
+    if args[:silence] == false
+      puts "*Note: the reindex task will remove your current indexes and start from scratch."
+      puts "If you have a large dataset, reindexing can take a very long time, possibly weeks."
+      puts "This is not encouraged if you have anywhere near or over 1 million rows."
+      puts "Are you sure you want to drop your indexes and completely reindex? (y/n)"
+      answer = STDIN.gets.chomp
+      return false unless answer.match(/^y/)
+    end
 
     # Retry once or gracefully fail for a 5xx error so we don't break reindexing
     Sunspot.session = Sunspot::SessionProxy::Retry5xxSessionProxy.new(Sunspot.session)