title: Validate number 18.2 with class-validator
body: <p>I need to validate <code>number 18.2</code> with <a href="https://github.com/typestack/class-validator" rel="nofollow noreferrer">class-validator</a>. On current stage I know how to validate only decimal places:</p>
  <pre class="lang-js prettyprint-override"><code>export class PaymentBasicData {
      /**
       * Transaction amount.
       */
      @Expose()
      @IsNotEmpty()
      @IsNumber({ maxDecimalPlaces: 2 })
      @Min(0.01)
      @Max(999999999999999999.99)
      public amount: number;
  }
  </code></pre>
  <p>I should validate a <code>number</code> with 18 numbers before dot and 2 numbers after dot. How it should looks like?</p>