Returns true if the value of this BigNumber is greater than or equal to the value of n, otherwise returns false.

(0.3 - 0.2) >= 0.1                    // false
x = new BigNumber(0.3).minus(0.2)
x.gte(0.1)                            // true
BigNumber(1).gte(x)                   // true
BigNumber(10, 18).gte('i', 36)        // true