fix: Default the schema to an empty string

Author: elpete

models/QBMigrationManager.cfc

@@ -5,7 +5,7 @@ component accessors="true" {
     property name="defaultGrammar" default="AutoDiscover@qb";
     property name="datasource";
     property name="migrationsTable" default="cfmigrations";
-    property name="schema";
+    property name="schema" default="";
     property name="useTransactions" default="true";
 
     public QBMigrationManager function init() {

tests/specs/MigrationServiceSpec.cfc

@@ -10,7 +10,7 @@ component extends="tests.resources.ModuleIntegrationSpec" appMapping="/app" {
                 expect( manager.getDefaultGrammar() ).toBe( "AutoDiscover@qb" );
                 expect( manager.getDatasource() ).toBeNull();
                 expect( manager.getMigrationsTable() ).toBe( "cfmigrations" );
-                expect( manager.getSchema() ).toBeNull();
+                expect( manager.getSchema() ).toBe( "" );
                 expect( manager.getUseTransactions() ).toBeTrue();
             } );