add test for Gateway
add test for Gateway

jakejohns/Aura.SqlSchema,frederikbosch/Aura.Sql,JLacoude/Aura.Sql,cxj/Aura.SqlQuery,auraphp/Aura.Sql,dstockto/Aura.SqlQuery,paska27/sql-builder,gsouf/Aura.SqlQuery,auraphp/Aura.SqlQuery,sasha-ch/Aura.Sql,NateJacobs/Aura.Sql,harikt/Aura.SqlQuery,auraphp/Aura.SqlMapper_Bundle,auraphp/Aura.SqlSchema,ThisIsPuzzle/Aura.Sql,cxj/Aura.SqlMapper_Bundle