Fix DB migrations to allow rollbacks

Author: arcdigital

database/migrations/2017_08_05_144104_AllowNegativeValuesForOverallocation.php

@@ -23,8 +23,8 @@ public function up()
     public function down()
     {
         Schema::table('nodes', function (Blueprint $table) {
-            $table->mediumInteger('disk_overallocate')->unsigned()->nullable()->change();
-            $table->mediumInteger('memory_overallocate')->unsigned()->nullable()->change();
+            DB::statement('ALTER TABLE nodes MODIFY disk_overallocate MEDIUMINT UNSIGNED NULL, 
+                                             MODIFY memory_overallocate MEDIUMINT UNSIGNED NULL');
         });
     }
 }

database/migrations/2017_08_05_174811_SetAllocationUnqiueUsingMultipleFields.php

@@ -22,7 +22,9 @@ public function up()
     public function down()
     {
         Schema::table('allocations', function (Blueprint $table) {
+            $table->dropForeign(['node_id']);
             $table->dropUnique(['node_id', 'ip', 'port']);
+            $table->foreign('node_id')->references('id')->on('nodes');
         });
     }
 }