Add drop table if exists to the schema

schema.go

@@ -31,6 +31,16 @@ func (s *Schema) DropTable(name string, soft bool, option string) {
 	s.pool = append(s.pool, dropTableCommand{name, soft, option})
 }
 
+// DropTableIfExists removes table if exists from schema
+// Warning ⚠️ BC incompatible
+//
+// Example:
+//		var s migrator.Schema
+//		s.DropTableIfExists("test")
+func (s *Schema) DropTableIfExists(name string) {
+	s.pool = append(s.pool, dropTableCommand{name, true, ""})
+}
+
 // RenameTable executes command to rename table
 // Warning ⚠️ BC incompatible
 //

schema_test.go

@@ -31,6 +31,18 @@ func TestSchemaDropTable(t *testing.T) {
 	assert.Equal(dropTableCommand{"test", false, ""}, s.pool[0])
 }
 
+func TestSchemaDropTableIfExists(t *testing.T) {
+	assert := assert.New(t)
+
+	s := Schema{}
+	assert.Len(s.pool, 0)
+
+	s.DropTableIfExists("test")
+
+	assert.Len(s.pool, 1)
+	assert.Equal(dropTableCommand{"test", true, ""}, s.pool[0])
+}
+
 func TestSchemaRenameTable(t *testing.T) {
 	assert := assert.New(t)