**Inputs:**

1. A qubit in the $\ket{0}$ state.
2. Angle $\alpha$, in radians, represented as `Double`.

**Goal**: Change the state of the qubit to $\cos{α} \ket{0} + \sin{α} \ket{1}$.

<details>
  <summary><b>Need a hint?</b></summary>
  Experiment with rotation gates you learned about in the Single-Qubit Gates kata.
  Note that all rotation operators rotate the state by <i>half</i> of its angle argument.
</details>
