Add title and metadata to trial object

[alexsb]

Thinking about how we can generate good data from our experiments, I think we need a few more field in the trial object. Here's what we have right now.

 "dotplot-low": {
          // The description is used in the admin panel and not shown to particpants. 
          "description": "Task 1: low temperatures.",
          "instruction": '''

Here's what we should have:

 "dotplot-low": {
          // The description is used in the admin panel and not shown to particpants. 
          "title": "T1-low-temp"
          "properties": [
               temp: low,
               difficulty: 1,
               nr-dots: 18
          }
          "description": "Task 1: low temperatures.",
          "instruction": '''

The content of properties is a flat array of key-value pairs. These will then be mapped to observations in tidy data.

[alexsb]

Desired example output data:

trial;userID; timestamp; duration; answer; prop-temp; prop-difficulty; prop-nr-dots
T1-low-temp; 001; 12:00:01; 00:01:01; yes; low; 1; 18

[kirangadhave]

@dyr429, do we have any progress or plans on adding metadata to trials? I will implement the tidy-format download, but before that, we should fix the top-level key we will use for trial metadata.

If we have not decided on a key yet, metadata is a good option. I can add it to the reference spec and some trials for testing.

[dyr429]

Yes, I'm working on it. Should have it ready this afternoon

[kirangadhave]

cool