fix trial type bug in animation plugin
fix trial type bug in animation plugin

adrianoesch/jsPsych,wolfgangwalther/jsPsych,msrresearch/jsPsych,jspsych/jsPsych,jspsych/jsPsych,jodeleeuw/jsPsych,vergenzt/jsPsych,jspsych/jsPsych,Scienthusiast/jsPsych,andyh616/jsPsych,shamrt/jsPsych,adrianoesch/jsPsych,shamrt/jsPsych,erikasf/jsPsych,Scienthusiast/jsPsych,andyh616/jsPsych,erikasf/jsPsych,jspsych/jsPsych,wolfgangwalther/jsPsych,vergenzt/jsPsych