Don't use deprecated corrector apis

Closes #368

This is pretty much just a compatibility layer in itself.

Cops here are still declared with the old style (`autocorrect` instance method for example)
but rewriting that all is not trivial and also works just fine

lib/erb_lint/corrector.rb

@@ -1,14 +1,14 @@
 # frozen_string_literal: true
 
-require "rubocop/cop/legacy/corrector"
-
 module ERBLint
   class Corrector
     attr_reader :processed_source, :offenses, :corrected_content
 
     def initialize(processed_source, offenses)
       @processed_source = processed_source
       @offenses = offenses
+      corrector = RuboCop::Cop::Corrector.new(@processed_source.source_buffer)
+      correct!(corrector)
       @corrected_content = corrector.rewrite
     end
 
@@ -18,8 +18,10 @@ def corrections
       end.compact
     end
 
-    def corrector
-      ::RuboCop::Cop::Legacy::Corrector.new(@processed_source.source_buffer, corrections)
+    def correct!(corrector)
+      corrections.each do |correction|
+        correction.call(corrector)
+      end
     end
   end
 end