just use node 6.6 for now
just use node 6.6 for now

wolfgangwalther/jsPsych,jspsych/jsPsych,wolfgangwalther/jsPsych,jodeleeuw/jsPsych,jspsych/jsPsych,jspsych/jsPsych,msrresearch/jsPsych,jspsych/jsPsych