message: Add Decimal.minus() to declaration file
diff: @@ -24,6 +24,13 @@ export declare class Decimal {
  * Both values need to have the same fractional digits.
  */
  plus(b: Decimal): Decimal;
  + /**
  + * a.minus(b) returns a-b.
  + *
  + * Both values need to have the same fractional digits.
  + * The resulting difference needs to be non-negative.
  + */
  + minus(b: Decimal): Decimal;
  equals(b: Decimal): boolean;
  isLessThan(b: Decimal): boolean;
  isLessThanOrEqual(b: Decimal): boolean;
  