Fix migrations genterator

lib/generators/shotengai/migrations_generator.rb

@@ -17,16 +17,16 @@
           # Use sort() to order the migrations by seq 
           # Use [2..-1] to delete the seq
           Dir[ File.join(self.class.source_root, '*.rb') ].sort.each { |f| 
-            copy_migration File.basename(f, '.rb')[2..-1]
+            copy_migration File.basename(f, '.rb')
           }
         end
 
       protected
         def copy_migration(filename)
-          if self.class.migration_exists?("db/migrate", "#{filename}")
-            say_status("skipped", "Migration #{filename} already exists")
+          if self.class.migration_exists?("db/migrate", "#{filename[2..-1]}")
+            say_status("skipped", "Migration #{filename[2..-1]} already exists")
           else
-            migration_template "#{filename}.rb", "db/migrate/#{filename}.rb"
+            migration_template "#{filename}.rb", "db/migrate/#{filename[2..-1]}.rb"
           end
         end
       end