spinalCase("This Is Spinal Tap") should return "this-is-spinal-tap".
    testString: assert.deepEqual(spinalCase("This Is Spinal Tap"), "this-is-spinal-tap");
  - text: spinalCase("thisIsSpinalTap")  should return "this-is-spinal-tap".
    testString: assert.strictEqual(spinalCase('thisIsSpinalTap'), "this-is-spinal-tap");
  - text: spinalCase("The_Andy_Griffith_Show")  should return "the-andy-griffith-show".
    testString: assert.strictEqual(spinalCase("The_Andy_Griffith_Show"), "the-andy-griffith-show");
  - text: spinalCase("Teletubbies say Eh-oh") should return "teletubbies-say-eh-oh".
    testString: assert.strictEqual(spinalCase("Teletubbies say Eh-oh"), "teletubbies-say-eh-oh");
  - text: spinalCase("AllThe-small Things") should return "all-the-small-things".
    testString: assert.strictEqual(spinalCase("AllThe-small Things"), "all-the-small-things");
```