This behaves like math.random except that it uses true random numbers derived from the ESP8266 hardware. It returns uniformly distributed
numbers in the required range. It also takes care to get large ranges correct.
It can be called in three ways. Without arguments in the floating point build of NodeMCU, it returns a random real number with uniform distribution in the interval [0,1).
When called with only one argument, an integer n, it returns an integer random number x such that 1 <= x <= n. For instance, you can simulate the result of a die with random(6).
Finally, random can be called with two integer arguments, l and u, to get a pseudo-random integer x such that l <= x <= u.
#### Syntax
`node.random()`
`node.random(n)`
`node.random(l, u)`
#### Parameters
- `n` the number of distinct integer values that can be returned -- in the (inclusive) range 1 .. `n`
- `l` the lower bound of the range
- `u` the upper bound of the range
#### Returns
The random number in the appropriate range. Note that the zero argument form will always return 0 in the integer build.