test(curriculum): use Mocha for tests

curriculum/test/utils/challengeTitles.js

@@ -0,0 +1,27 @@
+class ChallengeTitles {
+  constructor() {
+    this.knownTitles = [];
+  }
+  check(title) {
+    if (typeof title !== 'string') {
+      throw new Error(
+        `Expected a valid string for ${title}, but got a(n) ${typeof title}`
+      );
+    }
+    const titleToCheck = title.replace(/\s+/g, '').toLowerCase();
+    if (titleToCheck.length === 0) {
+      throw new Error('Expected a title length greater than 0');
+    }
+    const isKnown = this.knownTitles.includes(titleToCheck);
+    if (isKnown) {
+      throw new Error(`
+    All challenges must have a unique title.
+
+    The title ${title} is already assigned
+    `);
+    }
+    this.knownTitles = [ ...this.knownTitles, titleToCheck ];
+  }
+}
+
+module.exports = ChallengeTitles;