Merge pull request #5012 from waseem/alias-reconnect-mysql2

Alias reconnect! to reset! for Mysql2 adapter since they have same behavior.

activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb

@@ -80,6 +80,7 @@ def reconnect!
         disconnect!
         connect
       end
+      alias :reset! :reconnect!
 
       # Disconnects from the database if already connected.
       # Otherwise, this method does nothing.
@@ -90,11 +91,6 @@ def disconnect!
         end
       end
 
-      def reset!
-        disconnect!
-        connect
-      end
-
       # DATABASE STATEMENTS ======================================
 
       def explain(arel, binds = [])