title: Sequelize in NodeJS : Inner JOIN implementation Failure
body: <p>I have three tables contractors, projects and jointable for these two is projects_contractors and i created models and wrote a relation like below,</p>
  
  <pre><code>    Contractor.hasMany(Project, {joinTableName: 'projects_contractors'})
      Project.hasMany(Contractor, {joinTableName: 'projects_contractors'})
  </code></pre>
  
  <p>I want to access this Contractor based projects means inner JOIN.</p>
  
  <p>Core query : 
                   select c.id,c.name,p.id,p.name from contractors c inner join projects_contractors pc on c.id=pc.contractor_id inner join projects p  on p.id = pc.project_id</p>
  
  <p>I was failed in implementing the below code. "required" is a keyword which used for inner JOIN but not working if we keep.</p>
  
  <pre><code>     Contractor.findAll({ include: [Project, {required: false}]}).success(function(list){
         console.log("hi")
           res.send(204)
       })
  </code></pre>
  
  <p>If not keeping required it will creates a left outer JOIN on projects and contractors.  Suggest me with a sample example for the above senario. </p>