[beta] Add mechanism to encourage contributions to codebase

Issue Description

As a developer, having a notification on beta challenges that tests are incomplete would help me find issues to work on.

As a product owner, having a notification of missing tests on beta challenges will reduce the number of incoming tickets and duplicate tickets because users will know the challenge is incomplete.

Additionally, I think this could be easier for users to spot opportunities to work on the project.

example:

      "id": "587d7b89367417b2b2512b48",
      "title": "Use the Spread Operator",
      "description": [
        "ES6 introduces the <dfn>spread operator</dfn>, which allows us to expand arrays and other expressions in places where multiple parameters or elements are expected.",
        "The ES5 code below uses <code>apply()</code> to compute the maximum value in an array:",
        "<blockquote>var arr = [6, 89, 3, 45];<br>var maximus = Math.max.apply(null, arr); // returns 89</blockquote>",
        "We had to use <code>Math.max.apply(null, arr)</code> because <code>Math.max(arr)</code> returns <code>NaN</code>. <code>Math.max()</code> expects comma-separated arguments, but not an array.",
        "The spread operator makes this syntax much better to read and maintain.",
        "<blockquote>const arr = [6, 89, 3, 45];<br>const maximus = Math.max(...arr); // returns 89</blockquote>",
        "<code>...arr</code> returns an unpacked array. In other words, it <em>spreads</em> the array.",
        "However, the spread operator only works in-place, like in an argument to a function or in an array literal. The following code will not work:",
        "<blockquote>const spreaded = ...arr; // will throw a syntax error</blockquote>",
        "<hr>",
        "Copy all contents of <code>arr1</code> into another array <code>arr2</code> using the spread operator."
      ],
      "challengeSeed": [
        "const arr1 = ['JAN', 'FEB', 'MAR', 'APR', 'MAY'];",
        "const arr2 = [];",
        "// change code below this line",
        "// change code above this line",
        "arr1.push('JUN');",
        "console.log(arr2); // arr2 should not be affected"
      ],
      "tests": [
        "// Test arr2 is correct copy of arr1",
        "// Test arr1 has changed",
        "// Test spread operator was used"
      ]

[raisedadead]

Is there any kind of formal way to propose a feature to the core contributors?

Yes, you can create issues on this issue tracker. We will triage as deemed necessary.

[JosephLivengood]

In addition, this could also be a good use of the Projects feature of Github to keep it organized on here and connect them to issues or pulls or assigning!