Changed the `migration_style` config setting to `migration_type`

Signed-off-by: Jonathon Hill <jhill@brandmovers.com>
diff --git a/application/config/migration.php b/application/config/migration.php
index 476da1b..3ea3ef9 100644
--- a/application/config/migration.php
+++ b/application/config/migration.php
@@ -39,7 +39,7 @@
 
 /*
 |--------------------------------------------------------------------------
-| Migration Style
+| Migration Type
 |--------------------------------------------------------------------------
 |
 | Migration file names may be based on a sequential identifier or on
@@ -53,7 +53,7 @@
 | to 'sequential' for backward compatibility.
 |
 */
-$config['migration_style'] = 'timestamp';
+$config['migration_type'] = 'timestamp';
 
 /*
 |--------------------------------------------------------------------------